Electrophilic reactions of alpha;-amino dienenitriles: regiochemistry and stereoselectivity of trisubstituted pentadienyl anions

摘要

J. CHEM. SOC. PERKIN TRANS. I 1992 Electroph i Iic React ions of a-Amino Dienen itri les: Regiochem istry and Stereoselectivity of Trisubstituted Pentadienyl Anions Chau-Chen Yang and Jim-Min Fang" Department of Chemistry, Nationa f Taiwan University, Taipei, Taiwan 7 0764, Republic of China A pentadienyl anion 7a generated from 2-N-methylanilinohepta-3,5-dienenitrile reacted at the y-site with halogenoalkanes to give predominantly the products 9y-22y having the 2Z,5euro;-configuration, while it reacted at the amp;-site with conjugated aldehydes to give mainly the products 27r-29e having the 2Z,4euro;-configuration. An intermediate of the pentadienyl ion 7a having a lithium atom a-bonded to the y-carbon and chelated with the anilino group was proposed to account for the regio- and stereo-selectivities observed in the above reactions. The alkylation reactions in the presence of a dipolar co-solvent HMPA tended to enhance the 2Z-selectivity.The pentadienyl anions derived from the a-anilino dienenitriles 30-33 having different c-substituents such as phenyl, phenylthio, benzyloxy and ethoxycarbonyl groups also reacted with halides and aldehydes both regio- and stereo-selectively. Dithioacetal, cyanohydrin derivatives and a-amino nitrile are three widely used synthetic umpolungs of acyl groups.' The regiochemistry of corresponding allylic anions toward electro- philes has been extensively studied. These anions can function as equivalents of a$-unsaturated acyl anions if reactions occur at the a-sites, or they can function as equivalents of p-anions of carboxylic acids if reactions take place at the y-sites.The allylic I I 2a Y = N(CHamp;OCH2CHz 3 2b Y = NMePh Me-CN OSiMeg 6a n=O bn=l cn=2 anions of cyanohydrin derivatives 1 appear to react invariably at the but the regioselectivity of the allylic anions of dithioacetal and aminonitrile is controlled by many factors, including the size of the SR or NRR' group.3 For example, the anion of 2-morpholinopent-3-enenitrile2a reacts exclusively at the a-site with ha loge no alkane^,^' while alkylation of the anion of 2-N-methylanilinopent-3-enenitrile2boccurs at the y-~ite.~~" The a-alkylation is disfavoured in the latter case due to the steric hindrance of the bulky N-methylanilino group.Similar tuents is rarely investigated. Hunig and his co-workers have reported that the pentadienyl anion of cyanohydrin trimethylsil- yl ether 4 undergoes alkylation exclusively at the a-site.6 A study of dithiane pentadienyl anions such as 5 also indicates the a-selectivity in electrophilic reactions. 'It has been shown that the phenylsulfinyl- and phenylsulfonyl-substitutedpentadienyl anions 6b,c react at the a-sites with iodomethane and carbonyl compounds whereas the regiochemistry of the corresponding phenylsulfenyl-substitutedanion 6a is dependent on the electro- phile.8 We describe herein the pentadienyl anions of the a-amino nitrile 7 and the related compounds 30-33, which, depending on the electrophile, are preferentially attacked at the a-, y-or amp;-sites.Results and Discussion 2-N-Methylanilinohepta-3,5-dienenitrile7 was prepared by condensation of hexa-2,4-dienal, potassium cyanide and N-methylaniline according to Strecker's method.' The 3E,SE-~onfiguration was characterised by the large coupling constants, J3,416 Hz and J5,6 15 Hz, in the NMR spectrum. Deprotonation of 7 with lithium diisopropylamide (LDA) in THF at -78 "C gave a pentadienyl anion 7a,which sub- sequently reacted with a variety of electrophiles as shown in Table 1. The reactions with D20 and aldehydes (entries 1 and 19-23) were quenched at -78 "C, while the other reaction mixtures were allowed to warm to room temperature. When D,O was used as the electrophile, only the a-deuteriated compound 8a was obtained. The anion 7a reacted with oxygen at both terminal sites but not at the central y-site (entry 18).The a-product was isolated as the corresponding amide, N-methyl- N-phenylhexa-2,4-dienamide24a.'' On the other hand, the alkylations with halides occurred at the y-site to give two geometric isomers predominating in the 22-configuration (entries 2-16). The 2Z-isomer was consistently more polar than phenomena are observed in the reactions of 1,l-dithio-substi- the corresponding E-isomer. The 3-H resonance of the 2Z- tuted allylic anions 3,i.e.an increase in the size of the substituent isomer usually occurred at a lower field (-6 6.2) due to the on sulfur tends to increase the proportion of the y-rea~tion.~",~ deshielding effect of the cyano group." The anion 7a reacted If the substituent is a pentadienyl system, the anion may react with electrophiles at the a-, y-or amp;-site.Many studies have concerned the reactivity of the parent pentadienyl anion and those having alkyl sub~titutents.~ The regioselectivity of penta- dienyl anions is apparently dependent on the substituents in addition to other controlling factors. Utilisation of pentadienyl anions in synthesis of natural products has also been reali~ed.~ However, the pentadienyl anion having heteroatom substi- with aliphatic aldehydes at -78 "C to give the y-and amp;-addition products predominating in the 22-isomers. However, 7areacted with conjugated aldehydes exclusively at the amp;-site to give the 22,4E-products, of which 3-H and C-3 appearing at low fields (approximately d,., 6.6 and dc 145, respectively) indicated the 2Z-configuration and the large coupling constant (J4,516 Hz) supported the 4E-config~ration.'~ The alkylations in the presence of a dipolar co-solvent J.CHEM. SOC. PERKIN TRANS. 1 1992 MewN NMePh ' NMePh 7 7a Eledrcphile1 Me*N + M e w N NMePh E NMePh E NMePh a-produd8a Table 1 Electrophilic reactions of the pentadienyl anion 7a in THF (Scheme 1)" ~~~ ~~ ~ Entry Electrophile Product (isolated yield) () E 1 D2O 8a (95) D 2 Me1 9yE(37) + 9yZ(53) Me 3 EtI lOyE(33) + lO~Z(41)~ Et 4 Me,CHI llyE(30) + llyZ(41) Me,CH 5 PhCH,CI 12yE (29) + 12yZ (38) PhCH, 6 CH,=CHCH,Br 13yE(19) + 13yZ(36) + 13tZ(9) CH,SHCH, 7 PhCH=euro;HCH,CI 14yE(30) + 14yZ(44) PhCHSHCH, 8 EtO,CCH,Br lsyE(4) + 15yZ(80) EtO,CCH, 9 BrCH,CH,Br 16yE(10) + 16yZ(13)' BrCH,CH, 11 Br(CH 2)3 Br 17yE(36) + 17yZ(53) Br(CH2)312 BrCHSHCH,Br 18yE(35) + lSyZ(41) BrCHSHCH, 13 Br(CH,),CHBrMe 19yE(31) + 19yZ(43) (CH2),CHBrMe 14 Br(CH,),Br 2OyE (28) + 20yZ(45) Br(CH21, 15 CH,(CH,),C(Br)==kH2C1 21yE (16) + 21yZ(66)' amp;H,(CH,),C(Br)amp;CH, 16 o-BrC,H,CH,Br 22yE (25) + 22yZ (70) o-BrC,H,CH, 17 PhSSPh 23rE (52) PhS 18 02 24a(15)/ + 24cE(5) + 24~Z(64) OH 19 MeCH,CHO 25yE(28) + 25yZ(38) + 25~Z(26)~ MeCH,CH(OH) 20 Me(CH,),CHO 26yE (28) + 26yZ (53)g.h Me(CH,),CH(OH) 21 PhCHO 2762 (85) PhCH(0H) 22 MeCHSHCHO 28rZ (69) MeCH=CHCH(OH) (79) PhCHHCH(OH)23 PhCHXHCHO 29~Z ~ " The reactions with D20and aldehydes (entries 1 and 19-23) were quenched at -78 "C, while the reactions of other entries were allowed to warm to room temperature.Reaction in the presence of 3 equiv. HMPA gave lOyE (22) + lOyZ (65). 'Starting material 7 (43) was recovered. Reaction performed in the presence of 3 equiv. HMPA. Reaction in the presence of 3 equiv. HMPA gave 23yE (25) + 23rE (25 + 2362 (43). =-Product isolated as N-methyl-N-phenylhexa-2,4-dienamide.Products consisted of the erythro-and threo-isomers. Reaction gave 26yE (44) + 26y2(28) when the reaction was warmed to -40 "C for 2 h. while it gave 26yE (21) + 26yZ(27) + 26eZ(13) after being stirred for 1 h at room temp. Table 2 Effects of co-solvent HMPA and temperature on the reactions of the pentadienyl anion 7a with electrophiles in THF Electrophile HMPA (equiv.) T/"C (time/h) Products ratio ~~~~ ~ ~ EtI 0 -78 to 25 10, yE:yZ = 45: 55 3 -78 to 25 10, yE:yZ = 25:75 PhSSPh 0 -78 (1) 23,yZ:rE:~Z= 17: 17: 17" 0 -78 to 0 23,yZ:tE:rZ = 7:40:53 3 -78 to 25 (0.5) 23,yz:~E:~Z= 26:26:48 0 -78 to 25 (2) 23, rE:rZ = 55:45 0 -78 to 25 (16) 23, rE (100) Me(CH,),CHO 0 -78 26, yE: yZ = 35 :65 0 -78 to -40(2) 26, yE:yZ = 60:40 0 -78 to 25 (1) 26,yE:yZ:~Z= 34:44:21 " Starting material 7 was recovered (49).hexamethylphosphoramide (HMPA) (3 equiv.), e.g. entries 15 presence of HMPA tended to increase the proportion of the 22-and 16, appeared to give a higher ratio of the 22-isomers of the isomer of 1Oy.The anion 7a reacted sluggishly with diphenyl y-products. Effects of HMPA and temperature on the reactions disulfide at -78 "C to give equal amounts of the yZ-, cE-and of 7a with representative electrophiles such as iodoethane, euro;2-isomers of 23 in addition to recovered starting material. diphenyl disulfide and butyraldehyde were investigated, and the However, a 16 h reaction with stirring at room temperature results are shown in Table 2. The reaction with EtI in the occurred predominantly at the amp;-site and led to a single product J. CHEM. SOC. PERKIN TRANS. 1 1992 23~Ehaving the 2E,4E-configuration. When the reaction of 7a with butyraldehyde was warmed to room temperature, 2662 was also obtained as a minor product in addition to the y-products.A parent pentadienyl anion is commonly considered to have three geometries for the qs-coordination structure: the zigzag- like W-shape, the horseshoe U-shape and the sickle-like S-shape.5 For example, pentadienyllithium exists as the W-shaped duct after a prolonged reaction time. For a similar reason, the y-addition mode in the reaction of 7a with butyraldehyde at -78 "C was partially changed to the amp;-addition mode at room temperature. The exclusive formation of the amp;-addition products in the reactions of 7a and conjugated aldehydes (entries 21-23, Table 1) might be attributable to their highly reversible reaction. The pentadienyl anions of the aminonitriles 30-33 having different amp;-substituents (Y) were also investigated (Table 3).The anion derived from 30 (Y = Ph) was treated with o-bromobenzyl bromide in the presence of HMPA to give exclusively the y-product 34y predominating in the 22,5E- 0 v isomer. However, a similar alkylation of 31 (Y = PhS) having Me2YNMePhNMePh W-shaped q5-strudure S-shaped q5-structure NMePh S-shaped q5-strudure U-shaped q5-structure structure while pentadienylpotassium exists as the U-shaped structure in THF solution.12 In principle, the amino nitrile pentadienyl anion 7a may have 16 q'-coordination forms which consist of four W-, four U-and eight S-shaped struc- tures. However, the possible delocalisation by the cyano group,Ie and even the existence of ql- and q3-coordination structures should not be overlooked.In such cases, the ql-,q3-and qs-forms may also undergo equilibrium. It is thus difficult to predict the reactivity of a pentadienyl anion due to its possible existence of various coordination states. However, the observed regio- and stereo-selective reaction modes in the pen tadien yl system of 7a point to a probable W-shaped intermediate A, which is stabilised by having lithium atom o-bonded to the y-carbon and coordinated with the a-amino group.13 This model explains the preference for formation of the 22-isomers in electrophilic reactions with halogenoalkanes and aldehydes regardless of the reactions occurring at either the y-or amp;-site. Except for the small electrophiles, e.g. D20and 02,reactions at the a-site were impeded by the bulky N-methylanilino group.A similar model has been proposed to account for the y-and 22- selectivity found in the reactions of an asymmetric allyllithium generated from 2-(N-methylanilino)-4-phenylbut-3-enenitrile.l4 The stereochemical outcome in asymmetric alkylations of a chiral ephedrino alkenenitrile further supports the ql-chelated form as a favourable intermediate.14 The preceding tationale is based on considering the reaction proceeding with a monomeric A, rather than the solvated free anion or the aggregate form. Although the effect of solvents was not thoroughly studied, a dipolar solvent HMPA might help to eliminate the degree of aggregate of A species to attain higher reactivity and better 2Z-~electivity.'~*' In the reaction of 7a with diphenyl disulfide, the proportion of the amp;-products increased at the expense of the y-product as the temperature and time increased.The amp;-product 23t incorp-orating the conjugated dienenitrile moiety is conceivably more stable than the y-product 23y.Thus the reaction of 7a and diphenyl disulfide is considered to involve a reversible process, and finally yielded the thermodynamically favoured 23eEpro-the 2E,4E-configuration retained the 2E-configuration in the y-product 35y.Interestingly, the alkylated products 36y and 37y of 32 (Y= PhCH,O) not only had the 2Z-configuration but also showed preference in the 52-configuration. A chelated intermediate B may be deduced to account for the stereochemical outcome:16 The anion of 33 (Y = C0,Et) fyy" PhCH,O-Li-NMePh B reacted with both a halide and an aldehyde at the carbon adjacent to the ethoxycarbonyl group.This regioselectivity is presumably affected by the potent stabilising ability of the ethoxycarbonyl group as usually observed in the reactions of crotonate anions.' Nonetheless, the amp;-products 38t-40~also prevailed in the 22-isomers. In summary, we have shown the reactions of pentadienyl anions generated from the amino nitriles 7and 30-33 are regio- and stereo-selective. The regiochemistry in reactions of 7a is dependent on the attacking electrophiles. The selective y-alkylations in 7a are different from the a-reactions of the pentadienyl anions derived from the silyloxy nitrile 5 and the dithiane 6.To demonstrate 7 as an equivalent of y,amp;-unsatur- ated carboxylic acid, the y-products 25y and 26y obtained from the reactions with the aldehydes were subsequently hydrolysed to afford the P-propenyl-y-lactones 41 and 42, MeCH=CH, MeCH=CH Et Prbo 41 42 respectively.On the other hand, the amp;-selective reactions furnished a-amino nitrile dienes such as 236and 27~-296,which can be utilised in 4 + 2cycloadditions9 and as precursors of the corresponding trienes. We are investigating the intra- molecular radical cyclisations of the y-products 17y-22y having bromoalkyl substituents in order to evaluate the stabilising power of captodative substitution.I8 Experimental M.p.s are not corrected. 'H NMR spectra were recorded at 200 or 300 MHz and 13C NMR at 50 or 75 MHz using chlorotrimethylsilane as internal standard (J values in Hz).Mass spectra (using a Finnigan TSQ 46c spectrometer) were recorded at an ionising voltage of 70 eV. Merck silica gel 60F sheets were used for analytical thin-layer chromatography (TLC). Column chromatography was performed on SiO, (70-230 mesh) with elution of gradients of EtOAc and hexane. High- pressure liquid chromatography (HPLC) was carried out on a liquid chromatograph, equipped with a refractive index detector. The samples were analysed and/or separated on a Hibar Lichrosorb Si 60 (7 pm) column (25cm x 1 cm) by the 3088 J. CHEM. SOC. PERKIN TRANS. 1 1992 Table 3 k NMePh Y T c N LDA, THF. (HMPA).Elearuphile,-78 "c -momtemp.y-producl341L37y + NMePh 30-33 y y w yCN E NMePh amp;-prodUCt 38~40~ Reactant Y Electrophile Product (yield) rA),isomeric ratio E 30' Ph o-BrC,H,CH,Br 34y (41), 2E,5E:2ZY5E = 33:67 o-BrC,H,CH, 31 PhS o-BrC,H,CH,Br 35y (68), 2E,5E only o-BrC,H,CH, 32 PhCH,O o-BrC,H,CH,Br 36y (61), 2Z,5E: 2Z,5Z = 33 :67 o-Bamp;amp;CH, 32 PhCH,O Br(CH,)J 37y (41), 2Z,5Z only Br(CH,), or I(CH,), 33 C0,Et EtI 386 (29), 2E,4E:2Z,4E = 59:41 + Et 39s (64)! 2Ey4E:2Z,4E = 36:64 33 C0,Et EtCHO 40e (98), 22,4E only EtCHOH a Alkylation reactions were performed in the presence of HMPA (3 equiv.) and the reaction mixture was stirred at room temp. for 4 h before work- up. The addition reaction with propionaldehyde was carried out at -78 "C for 0.5 h in the absence of HMPA.'The reactant was composed of (2E,4E)- and (2Z,4E)-2-(N-methylanilino)-6-phenylhexa-2,4-dienenitrilesas well as the non-conjugated isomers (2EY5E)- and (2ZY5E)-2-(N- methylanilino)-6-phenylhexa-2,5-dienenitrilesin a ratio of 22 :33:20: 25. The reactant had the (2EY4E)-configuration. The reactant was composed of the (2EY4Z)- and (22,4Z)-isomers in a ratio of 43:57. 'The reactant was composed of the (2E,4E)-and (22,4E)-komers in a ratio of 30:70. Compound 39cis the double alkylated product. indicated eluent with 5 cm3 mid flow rate. THF was distilled action with the electrophile of D20or aldehyde was quenched from sodium benzophenone ketyl under N,. 2-Bromo-1-at -78 "C after 30 min by addition of a THF solution of HOAc chloromethylcyclopentene, for entry 15 was prepared from 2- (3 mmol).Otherwise, the reaction with the electrophile of alkyl bromocyclopentenecarbaldehyde by reduction with NaBH, halide or PhSSPh or 0,was warmed to room temperature and and subsequent treatment with TsCl-Et3N. kept for a further 2 h before quenching with saturated aqueous NH4Cl. The mixture was concentrated under reduced pressure, Preparation of a-Amino Dienenitriles 7 and 30-33.-2-N-and the residue was taken up with EtOAc. The organic phase Methylanilinohepta-3,5-dienenitrile7 was prepared by conden- was washed with brine, dried (Na2S0,), and concentrated sation of hexa-2P-diena1, potassium cyanide and N-methyl- under reduced pressure to give the crude products. Separation aniline according to the Strecker's method.' Condensation of 2-of products was accomplished by column chromatography (N-methylanilino)prop-2-enenitrilewith phenylacetaldehyde (SiO,) and/or HPLC with elution of the gradients of EtOAc in (LDA, THF) afforded an alcohol, which was activated as the hexane indicated in each case.The reactions of the pentadienyl methanesulfonate (Et3N, MsCl) and treated with BU'OK to give anions of 3633 were carried out by similar procedures. 2-(N-methylanilino)-6-phenylhexa-2,4-dienenitrile30 and the non-conjugated isomer, 2-(N-methylanilino)-6-phenylhexa-2,5-Hydrolysis of Compounds 25y and 26y.-A solution of com-dienenitrile. Preparation of 2-(N-methylanilino)-6-phenyl-pound 2 (170 mg, mixture of diastereoisomers) in THF (2 thiohe~a-2~4-dienenitrile31 was achieved by the reaction cm3) and HCl(2 mol dm-3, 10 cm3) was heated to 70 "C under of 2-(N-methylanilino)-2-phenylthioacetonitrilewith 1,4-di-mild reflux for 16 h.The mixture was cooled, and extracted with bromobut-2-ene (Bu'OK, THF).,' The product 31 was EtOAc. The combined extracts were washed with aqueous accessed by a tandem alkylation-dehydrosulfenylation, fol-NaOH (5) and brine, dried (Na,SO,) and concentrated under lowed by a reinsertion of the benzenethiolate ion. Condensation reduced pressure. The residue was separated on a SiO, column of (N-methylani1ino)acetonitrile with (Z)-4-benzyloxybut-2-by elution with EtOAc (10 in hexane) to give the lactone 41 enal, which was obtained from oxidation of (Z)-4-benzyl-(90 mg, 92, translcis = 1.4).Hydrolysis of compound 26y oxybut-2-en01 (Mn02, CH,C1,),21 directly yielded 6-(270 mg, 0.77 mmol) by a similar procedure afforded the lactone benzyloxy-2-(N-methylanilino)hexa-2,4-dienenitrile32 accord- 42 (122 mg, 94, translcis = 1.5). ing to the Peterson procedure.' Condensation of ethyl 6- 2-(N-methylanilin0)2-~H)hepta-3,5-dienenitrile8a. Yellow 0xohexa-2,4-dienoate,~~ N-methylaniline and potassium cy- oil; HPLC (1 EtOAc in hexane) tR430 s; v,,,(neat)/cm-' 2232 anide, by a concurrent isomerisation, produced ethyl 6-cyano-6- (CN); GH(CDC13) 1.82 (3 H, d, J 6.0, 7-H), 2.84 (3 H, s, N-Me), (N-methylanilino)hexa-3,5-dienoate33. 5.54 (1 H, d, J 15,3-H), 5.90 (1 H, dq, J 15,6,6-H), 6.13 (1 H, br dd, J 15,10,5-H), 6.60 (1 H, dd, J 15,10,4-H), 6.92-7.00 (3 H, m) Reaction of Pentadienyl Anion with Electrophi1es.-U nder an and 7.24-7.34 (2 H, m); G,(CDC13) 18.1 (q, C-7), 34.3 (q, N-C), atmosphere of N,, a solution of diisopropylamine (0.18 cm3, 1.1 55.3 (t, C-2), 115.8 (s, C-l), 116.5 (d, 2 C, C-29, 116.6 (d), 120.8 mmol) in THF (10 cm3) was cooled to -15 "C and a solution (d), 121.6 (d), 129.3 (d, 2 C, C-37, 133.1 (d), 135.2 (d) and 148.6 of BuLi (1.6 mol dm-3 in hexane; 0.7 cm3, 1.1 mmol) was (s, C-1'); m/z 213 (M', 27), 198 (23), 106 (72) and 77 (100) added dropwise.After 15 min, the LDA solution was cooled to (M+, 213.1370. My213.1376). -78 "C, and a solution of compound 7(212 mg, 1.0 mmol) in 4-Methyl-2-(N-methylanilino)hepta-2,5-dienenitrile9y.E-Iso-THF (5 cm3) was added dropwise. The resulting orange-mer: yellow oil; TLC (2 EtOAc in hexane) R, 0.15; v,,,-coloured solution of 7a was stirred for 45 min, and treated at (neat)/cm-' 2240 (CN); GH(CDC13) 1.18 (3 H, d, J 7), 1.68 (3 -78 "C with an appropriate electrophile (1.2 mmol) accom- H, dd, J 6, 1,7-H), 3.1 1 (3 H, s, N-Me), 3.31-3.51 (1 H, m, 4-H), panied by HMPA (3 mmol) in certain cases (Table l). The re- 5.48 (1 H, ddq, J 18,6,1,5-H), 5.33-5.74 (1 H, m, 6-H), 5.69 (1 H, J. CHEM. SOC. PERKIN TRANS. 1 1992 d, J 10, 3-H),6.92-7.03(3 H, m) and 7.25-7.34 (2 H,m); amp;(CDCl,) 17.9 (q), 20.9 (q), 37.4(d), 39.9(q), 114.7(s), 119.3(d, 2C), 120.1(s), 122.2(d), 125.1(d), 129.2(d, 2C), 133.3(d), 137.2 (d) and 146.6(s); m/z 226(M', 59) and 211(100)(Found: C, 79.7;H, 8.0; N, 12.3.C15H18N2 requires C, 79.61;H, 8.02;N, 12.38).Z-Isomer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.12;v,,,(neat)/cm-' 2215(CN); 6,(CDC13) 1.07(3 H,d, J 7), 4-Allyl-2-(N-methylanilino)hepta-2,5-dienenitrile13y. E-Iso-mer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.13;vmax-(neat)/cm-' 2223(CN); G,(CDCl,) 1.69(3 H, d,J 6), 2.13-2.21 (1 H, m), 2.29-2.38(1 H,m), 3.10(3 H, s), 3.32-3.39(1 H,m), 4.98-5.09 (2 H,m), 5.37(1 H, dd, J 15,7), 5.54 (1 H, m), 5.64(1 H, d, Jlo),5.79(1 H,dq, J 15,6), 6.88-7.05 (3H,m) and 7.21-7.30 (2H, m); G,(CDCl,) 18.0(q), 40.0(t), 40.0(l), 42.9(d), 114.8(s), 1.64(3H,d,J6),3.06(3H,s),3.24-3.40(lH,m),5.18-5.49(2H,117.1(t), 119.2(s), 119.4(d, 2C), 122.3(d), 126.3(d), 129.2(d, 2 m),6.15(1H,d,J10),6.78(2H,dd,J7,1),6.88(1H,dd,J7,7) and 7.28 (2 H,ddd, J 7, 7, 1); Sc(CDC13) 17.9(q), 19.8(q), 35.1 (d),38.4(q), 114.2(d,2C), 116.2(s), 118.0(s), 119.7(d), 126.0(d), 129.2(d, 2C), 131.7(d), 146.2(s) and 149.4(d); m/z 226(M', 24) and 211 (Found: C, 79.9;H,7.95;N, 12.3).4-Ethyl-2-(N-methylanilino)hepta-2,5-dienenitrite1Oy. E-Iso-mer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.14;v,,,-(neat)/cm-' 2223 (CN); G,(CDCl,) 0.96(3 H,t, J 7), 1.37- 1.64(2H, m), 1.70(3 H,dd, J7,2),3.13(s), 3.35-3.63(1 H), 5.34 (1 H,dd, J 15,6), 5.53-5.63(1 H,m), 5.70(1 H,d, Jlo),6.94-7.02 (3 H, m) and 7.21-7.34 (2 H, m); amp;(CDCl,) 11.6(q), 18.0 (q), 28.5(t),40.0(q),44.9(d),114.8(s),119.1(d,2C),120.9(s),122.1 (d), 126.1(d), 129.2(d, 2C), 132.0(d), 136.6(d) and 146.6(d); m/z 240(M', 14) and 211 (100).Z-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.1 1; v,,,(neat)/cm-' 2212 (CN); amp;(CDCI,) 0.84(3H, t, J7.5), 1.35-1.48 (2 H, m), 1.65(3H,d, J 6),3.06(3H, s), 3.03-3.13(1 H,m), 5.23(1 H,ddd, J 15,7,l), 5.30-5.44(1H,m), 6.17(1 H,d, JlO), 6.78 (2 H,d, J7.5),6.89(1H,t, J7.5)and 7.28 (2 H, t, J7.5);Gc(CDC13) 11.6(q), 17.9(q), 27.6(t), 38.3(d), 42.8(q), 114.4(d, 2 C), 116.2(s), 118.8(s), 119.8(d), 127.1(d), 129.1(d, 2 C), 130.2(d), 146.2(s) and 148.4(d); m/z 240 (M', 15) and 211 (100)(M', 240.1626. M, 240.1626).4-lsopropyl-2-(N-methylanilino)hepta-2,5-dienenitrile1 1 y. E-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.14;v,,,-(neat)/cm-' 2223(CN); 6,(CDC13) 0.95(3H, d, J7), 0.96 (3H, d, J7), 1.63-1.77 (1 H,m), 1.70(3 H,dd, J6,l), 2.96-3.04(1 H,m), 3.13(3H,s),5.31(1H,ddd,J15,7,1),5.58(1H,dq,J15,6),5.79 (1 H, d, J 11, 3-H),6.87-7.11 (2 H, m) and 7.26-7.33 (2 H, m); Sc(CDCI3) 18.0(q), 19.9(q), 20.3(q), 32.9(d), 40.0(q), 50.4(d), 114.9(s), 118.9(d, 2C), 121.0(s), 122.0(d), 127.0(d), 129.9(d, 2 C), 130.8(d), 136.2(d) and 146.7(s); m/z 254(M', 18) and 211 (100).Z-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.10;v,,,(neat)/cm-' 2211 (CN); d~(cDC13) 0.86(3 H, d, J 7), 0.89(3H,d, J6), 1.56-1.70 (1 H, m), 1.66(3H, dd, J6,I), 2.86-2.99(1 H,m),3.04(3H,s),5.23(lH,ddd,J15,8,1),5.27-5.40(1H,m), 6.24(1 H, J ll), 6.77 (2 H, d, J8), 6.88 (1 H,t, J7)and 7.24-7.81 (2 H,m); 6,(CDC13) 18.0(q), 20.1(q), 20.3 (q), 32.2 (d), 38.2(q), 48.3(d), 114.4(d, 2C), 115.2(s), 118.9(d), 119.0(s), 119.8(d), 128.0(d), 129.1(d, 2C), 146.2(s) and 147.7(d);m/z254 (M', 21) and 211(M', 254.1781.M, 254.1783).4-Ben,?yl-2-(N-methylanitino)hepta-2,5-dienenitrile12y. E-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.12;v,,,-(neat)/cm-' 2222(CN); 6,(CDC13) 1.71(3H, J 6), 2.66 (1 H, dd, J 13,9), 2.99 (1 H, dd, J 13,6), 3.01(3H, s), 3.58-3.69(1 H, m), 5.46(1 H, dd, J 16,6.5),5.60(1 H,dq, J 16,6), 5.68 (1 H, d, J 10.5),6.66 (2 H, d, J7), 6.95 (1 H,t, J8)and 7.23-7.32 (7 H, m); Gc(CDC1,) 18.0(q), 39.8(q),42.0(t), 44.9(d), 114.6(s), 119.0(d), 121.4(s), 122.0(d), 126.3(d, 2C), 126.4(d), 128.4(d, 2C), 129.3 (d), 129.4(d, 2C), 131.5(d), 135.9(d), 138.7(s) and 146.5(s); m/z 302(M', 7) and 211 (100).2-Isomer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.09;v,,,(neat)/cm-' 2211 (CN); 6,-(CDCl3) 1.68(3H, d, J6), 2.63 (1 H, dd, J13,9),2.69(3H, s),2.84(1 H, dd, J13,5), 3.44-3.54(1 H,m), 5.41(2H, m), 6.20(1 H, d, Jlo), 6.52 (2 H,d, JS), 6.86 (1 H,t, J8), 7.08 (2 H,d, J8) and 7.20-7.32(5 H, m); Gc(CDC13) 18.0(q), 37.7(q), 41.4(t), 43.3(d), 1 14.5(d, 2C), 116.0(s), 118.0(s), 119.8(d), 126.4(d, 2 C), 127.2(d), 128.0(d, 2C), 129.0(d, 3 C), 129.9(d), 138.6(s), 146.2(d) and 147.1(d, C-3); m/z 302(M', 5) and 211 (100)(M', 302.1783.M, 302.1783).C), 131.5(d), 135.2(d), 135.4(d) and 146.5(s); m/z 252(M',, 4) and 211 (100).Z-Isomer: yellow oil; TLC (2 EtOAc in hexane) RF0.08; v,,,(neat)/cm-' 2212(CN); 6,(CDC13) 1.66(3 H, d, J 6), 2.12-2.23 (2 H, m), 3.06(3 H, s), 3.20-3.34(1 H, m), 4.94-5.12 (2 H,m), 5.29(1 H, dd, J 15,7), 5.42 (1 H, dq, J 15,6), 5.58-5.70(1 H,m), 6.16(1 H, d, J lo),6.79 (2 H, d, J8), 6.90(1 H, t, J7)and 7.27 (2 H, dd, J8,7);G,-(CDCl,) 17.9(q), 38.3(q), 39.0 (t), 40.8(d), 114.4(d, 2C), 116.1(s), 117.2(t), 119.0(s), 119.8(d), 127.2(d), 129.1(d, 2C), 129.8(d), 134.9(d), 146.1(s, C-1') and 147.5(d, C-3); m/z 252(M+,7) and 211(100).6-Methyl-2-(N-methylanilino)nona-2,4,8-trienenitrile13e. Z-Isomer: yellow oil: TLC (2 EtOAc in hexane) R, 0.05;v,,,-(neat) 2207(CN); 6,(CDC13) 0.97(3 H,d, J 7), 1.98-2.12 (2 H, m), 2.23-2.35(1 H, m), 3.12(3H,s), 4.90-5.06 (2 H, m), 5.60-5.75 (1 H, m), 6.03(1 H,dd, J 15,7,5-H), 6.25(1 H,dd, J15,11,4-H), 6.58(1 H, d, J 11,3-H),6.80(2H,d, J 8), 6.88(1 H, t, J8) and 7.27(2H,t, J8); Gc(CDC13) 19.3(q), 37.0(d), 38.6(q), 40.6(t), 114.8(d, 2C), 116.2(s), 116.6(t), 117.1(s), 120.0(d), 122.4(d), 129.3(d, 2C), 136.0(d), 143.0(d), 146.3(s) and 149.3(d); m/z 252(M', 8) and 211(100) (M+,252.1623.M, 252.1626). 4-Cinnamyl-2-(N-methylanilino)hepta-2,5-dienenitrile14y.E-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.09;v,,,-(neat)/cm-' 2222(CN); 6,(CDC13) 1.71(3H, dd, J6,l), 2.31(1 H, ddd, J 14, 8, 8), 2.46-2.58(1 H, m), 3.06(3H, s), 3.39-3.53(1H,m), 5.40(1 H,ddq, J 15,6,l), 5.60(1, H,dq, J 15,6), 5.70 (1 H, d, J lo),6.20(1 H, dtd, J 16, 8, 2), 6.41 (1 H,d, J 16),6.68-6.95(3H, m) and 7.09-7.40 (7 H,m); Gc(CDC1,) 18.0(q), 39.3 (t), 40.0(l), 43.3(d), 114.2(s), 119.2(d, 2C), 121.4(s), 122.1(d), 126.1(d, 2C), 126.4(d), 127.1(d), 127.2(d), 128.5(d, 2C), 129.1 (d, 2C), 131.5(d), 132.4(d), 135.5.(d), 137.2(s), and 146.4(s); m/z 328(Mf,1273, 327 (45) and 211 (100).Z-Isomer: yellow oil; TLC (2 EtOA3 in hexane) R, 0.05;v,,,(neat)/cm-' 2211 (CN); 6,(CDC13) 1.65(3H, dd, J6,l), 2.15-2.42 (2 H, m), 3.00 (3H, s), 3.27-3.43(1 H,m), 5.22-5.53 (2 H,m), 5.98(1 H, dt, J 16,6), 6.18 (1 H,d, Jlo), 6.35(1 H,dd, J 16, l), 6.72 (2 H, dd, J 8, l), 6.84(1 H, td, J8, 1) and 7.13-7.29 (7 H,m); G,(CDCl,) 19.0(q),38.3(t),38.4(1),41.3(d),114.4(d,2C),116.1(s),119.3 (s), 119.8(d), 126.0(d, 2C), 126.6(d), 127.2(d, 2C), 128.4(d, 2 C), 129.2(d, 2C), 129.8(d, 2C), 132.3(d), 136.9(s), 146.1(s) and 147.5(d, C-3); m/z 328(M', 0.273, 327 (2) and 211 (100) (M+, 328.1941.M, 328.1939).Ethyl3-(2-cyano-2-N-methylanilinovinyl)hex-4-enoate15y.E-Isomer: yellow oil; TLC (5 EtOAc in hexane) R, 0.06;v,,,-(neat of mixture)/cm-' 2213 (CN) and 1734(CO); G,(CDCl,) 1.27(3 H, t, J 7), 1.68 (3 H,d, J6), 2.50 (2 H, dd, J6,l), 3.11(3 H, s), 3.63-3.80(1 H, m), 4.13 (2 H, q), 5.30-5.60(2H, m), 5.58 (1 H, d, J lo), 6.90-7.10(3 H, m) and 7.30-7.45 (2 H); dC-(CDCl,) 14.0(q), 17.8(q), 38.2(d), 39.8(q), 40.3(t), 60.2(t), 114.6(s), 118.2(s), 122.8(d, 2C), 126.8(d), 127.0(d), 127.3(d, 2 C), 130.4(d), 130.7(d), 147.0(s) and 171.0(s).Z-Isomer: yellow oil; TLC (5 EtOAc in hexane) R, 0.06;6,(CDC13) 1.20(3 H,t, J7), 1.62 (3H, dd, J6,l), 2.41 (2 H, dd, J6,l), 3.07(3H,s), 3.58-3.71(1 H, m), 4.10(2 H, q,J 7), 5.20-5.50 (1 H, m), 5.35(1 H, dd, J 15,6), 6.21 (1 H, d, Jlo), 6.78 (2 H,dd, J7,l), 6.89(1 H, ddd, J 7, 7, 1) and 7.26 (2 H, ddd, J 7, 7, 1); amp;(CDCl,) 14.1(q), 17.8(q), 37.5(d), 38.3(q), 39.1(t), 60.5 (t), 114.7(d, 2C), 115.9(s), 119.7(s), 120.0(d), 128.0(d), 128.4 (d), 129.1(d, 2C), 145.4(d), 146.1(s) and 170.7(s); m/z 298 (M', 43), 297 (28) and 211 (100)(M', 298.1670.M, 298.1681).4-(2-BromoethyI)-2-(N-methyIaniIino)hepta-2,5-dienenitriIe 16y. E-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.10; v,,,(neat)/cm-' 2226 (CN); GH(CDC13) 1.70(3 H, dd, J 6, l), 1.94-2.08 (2 H, m), 3.12(3H, s), 3.80 (2 H, t, J 7), 5.863.45 (1 H, m), 5.28(1 H, ddq, J 15,8, l), 5.50 (1 H,d, J lo),5.64(1 H, dqd, J 15,6,l), 6.97-7.08(3 H, m) and 7.27-7.36 (2 H, m); Gc(CDCl3) 18.0(q), 30.3(t), 38.2(t), 40.2(q), 42.3(d), 114.4(s), 120.6(d, 2 C), 122.0(s), 123.2(d), 127.4(d), 129.3(d, 2 C), 130.5(d), 130.6(d) and 146.4(s); m/z 320 (M + 2+, 6), 318 (M+ for 79Br, 5) and 211 (100).Z-Isomer: oil; TLC (2 EtOAc in hexane) R, 0.06;vmax(neat)/cm-'2213(CN); G,(CDCl,) 1.64 (3H, dd, J6,l), 1.861.97 (2 H,m), 3.22(3 H, s), 3.28 (2 H, td, J7,l), 3.34-3.49(1 H, m), 5.16(1 H, ddq, J15,8, l), 5.43(1 H, dq, J 15,6),6.10(1 H, d, J lo), 6.78 (2 H, dd, J8, l), 6.90(1 H, t, J8) and 7.28 (2 H, t, J8); Gc(CDC13) 18.0(q), 30.2(t), 37.0 (t), 38.6(q), 39.9(d), 114.8(d, 2C), 116.0(s), 119.8(s), 120.2(d), 128.3(d), 128.8(d), 129.2(d, 2C), 145.5(d) and 146.1(s); m/z 320 (M + 2+, 679, 318 (M+ for 79Br, 6), 212 (14)and 211 (100) (M', 318.0720.M, 318.0732).4-(3-Bromopropyl)-2-(N-methyIaniIino)hepta-2,5-diene17y.E-Isomer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.12;vmax-(neat)/cm-' 2223(CN); GH(CDC1,) 1.47-1.62 (2 H, m), 1.70(3 H, d, J6), 1.81-1.94 (2 H, m), 3.12(3H, s), 3.18-3.30(1 H, m), 3.43(2H, t, J6),5.33(1 H, ddd, J 15,7, 2), 5.57 (1 H, dq, J 15, 6), 5.59 (1 H, d, J lo), 7.00-7.11(3 H, m) and 7.26-7.40 (2 H, m); Gc(CDC13) 17.4(q), 30.3(t), 33.4(t), 33.9(t), 40.0(q), 42.7 (d), 114.6(s), 119.7(d), 119.9(d, 2C), 121.2(s), 122.6(d), 126.5 (d), 129.1(d, 2C), 133.4(d) and 146.4(s); m/z 334 (M + 2+, 773, 332 (M+ for 79Br, 7)and 211 (100).2-Isomer: yellow oil; TLC (2 EtOAc in hexane) R,0.08; v,,,(neat)/cm-' 2211 (CN); ~H(CDCI~)1.42-1.60 (2 H, m), 1.60(3 H, d, J 7), 1.68-1.92 (2 H, m), 3.06(3H, s), 3.09-3.25(1 H, m), 3.31(2H, t, J7), 5.21 (1 H, ddd, J 15,6, I), 5.31-5.49(1 H, m), 6.13(1 H, d, Jlo), 6.77 (2 H, dd, J 8, l), 6.70(1 H, td, J 7, 1) and 7.28 (2 H, dd, J 7, 8); Gc(CDCl3) 17.9(q), 30.0(t), 32.8(t), 33.0(t), 38.4(q), 40.4(d), 114.5(d, 2C), 116.0(s), 119.1(s), 120.0(d), 127.8(d), 129.2(d, 2 C), 129.6(d), 146.1(s) and 147.2(d); m/z 334(M + 2+, 873, 332(M + for 79Br, 8) and 211 (100)(M+,332.0887.M, 332.0888).7-Bromo-2(N-methylanilino)-4-prop-1-enylhepta-2,6-diene-nitrife 18y. (2E,62)-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.13;vmax(neat)/cm-'2228(CN); SH(CDC1,) 1.70(3 H, dd, J6,2), 2.42 (2 H, ddd, J 7, 7, l), 3.12(3H, s), 3.38-3.48 (1 H, m), 5.40(1 H, ddq, J 15,6.5,l), 5.59(1 H, dq, J 15,6), 5.60(1 H, d, J lo), 6.13(1 H, dt, J7, 7), 6.29 (1 H, dt, J7,l), 6.95-7.07(3 H, m) and 7.27-7.35 (2 H, m); Gc(CDC1,) 18.0(q), 35.7(t), 40.1(d), 42.4(l), 109.8(d), 114.7(s), 120.3(d, 2C), 121.6(s), 122.9(d), 126.7(d), 129.2(d, 2C), 131.25(d), 131.7 (d), 132.1(d) and 146.4(s); m/z 332 (M + 23+,1l), 330(M+ for 79Br, 12)and 211 (100).(2E,6E)-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.11;v,,,(neat)/cm-' 2228 (CN); GH(CDC13)1.70(3H, dd, J 6, l), 2.10-2.39 (2 H, m), 3.12(3H, s), 3.27-3.44(1 H, m), 5.34(1 H, ddq, J 15,6,l), 5.54(1 H, d, Jlo), 5.58 (1 H, dq, J 15,6), 6.15 (1 H, d, J 14), 6.1M.27 (1 H, m), 6.96-7.07(3 H, m) and 7.28-7.36 (2 H, m); G,(CDCl,) 18.0 (q), 39.0(t), 40.1(d), 42.6(q), 106.5(d), 114.6(s), 120.2(d, 2C), 121.9(s), 122.9(d), 127.0(d), 129.3(d, 2C), 130.9(d), 132.3(d), 134.8(d) and 146.5(s); m/z 332 (M + 2+, 21), 331 (33), 330(M+ for 79Br, 29), 329 (31)and 211 (100).(62,2Z)-Isorner: yellow oil; TLC (2 EtOAc in hexane) R, 0.08; v,,,(neat)/cm-' 2216(CN); GH(CDCl,) 1.66(3 H, dd, J 6, l), 2.33 (2 H, ddd, J 7, 7, l), 3.07(3 H, s), 3.27-3.42(1 H, m), 5.20-5.52(2H,m),5.98(1H,dt,J7,7),6.19(1 H,d, J11),6.24 (1 H, dt, J7,l), 6.77 (2 H,d, J8), 6.90 (1 H, t, J8)and 7.28 (2 H, t, J8); Gc(CDC13)18.0(q), 34.6(t), 38.5(d), 40.2(q), 110.05 (d), 114.6(d, 2C), 116.0(s), 119.5(s), 120.1(d), 127.9(s), 129.3 (d, 2C), 129.4(d), 131.1(d), 146.2(s) and 146.6(d); m/z 332 (M + 2+, 28), 331 (34), 330 (M+ for 79Br, 32), 329 (30) and 211 (100).(6E,2Z)-Isomer: yellow oil; TLC (2 EtOAc in J.CHEM. SOC. PERKIN TRANS. 1 1992 hexane) R, 0.06;v,,,(neat)/cm-' 2216(CN); GH(CDC1,) 1.66(3 H, dd, J6,l), 2.01-2.24 (2 H, m), 3.06(3H, s), 3.19-3.34(1 H, m), 5.24(1 H, ddq, J 15,7,l), 5.43(1 H, dq, J 15,6), 5.99-6.17 (1 H, m), 6.05(1 H, d, Jll), 6.09(1 H, d, J 16), 6.77 (2 H, dd, J 8, l), 6.91(1 H, ddd, J 8, 8, 1) and 6.30 (2 H, ddd, J 8, 8, 1); Sc(CDC13) 18.0(q), 37.9(t), 38.4(d), 40.6(q), 106.7(d), 114.6 (d, 2C), 116.0(s), 119.0(s), 120.2(d), 128.0(d), 129.1(d), 129.3 (d, 2C), 134.4(d), 146.1(s) and 146.2(d); m/z 332(M + 2+, 29), 331 (38),330(M' for 79Br, 33,329 (27), 304 (20)and 211(100)(M+,330.0733.M, 330.0732). 4-(3-Bromobutyl)-2-(N-methyfaniIino)hepta-2,5-dienenitriIe 19y.-E-Isomer a: yellow oil; TLC (3 EtOAc in hexane) R, 0.15; v,,,(neat)/cm-' 2222 (CN); amp;(CDCI,) 1.50-1.91 (10H, m), 3.13(3 H, s), 3.17-3.28(1 H, m), 4.08-4.19(1 H, m), 5.29(1 H, ddq, J 15,6, l), 5.59(1 H, d, Jlo),5.60(1 H, dq, J 15,6), 6.97 (2 H, d, J8), 7.02(1 H,t, J 7.5) and 7.29 (2 H, dd, J 8, 7.5);Gc(CDC13) 18.0(q), 26.5(q), 33.6(t), 38.6(t), 40.1(q), 42.8(d), 51.3(d), 114.7(s), 119.9(d, 2C), 121.1(s), 122.7(d), 126.5(d), 129.2(d, 2C), 131.8(d), 133.7(d) and 146.5(s); m/z 348 (M + 2+, 2273, 347 (17), 346 (M+ for 79Br, 26), 345 (12)and 211 (100). E-Isomer b: oil; TLC (3 EtOAc in hexane) R'0.15;d,(CDCI,) 1.50-1.91(10H, m), 3.13(3H, s), 3.17-3.38 (1 H, m), 4.08419(1 H, m), 5.25(1 H, ddq, J 15,6,l), 5.57(1H,d, Jlo),5.61(1 H, dq, J 15,6), 6.97 (2 H, d, J8), 7.02 (1 H, t, J 7.5) and 7.29 (2 H, dd, J 8, 7.5);Gc(CDC13)18.0(q), 26.4(q), 33.5(t), 38.5(t), 40.1(q), 43.0(d), 51.2(d), 114.4(s), 119.7(d, 2 C), 120.9(s), 122.5(d), 126.7(d), 129.3(d, 2C), 131.6(d), 133.9 (d) and 146.5(s).Z-Isomer c: yellow oil; TLC (3 EtOAc in hexane) R, 0.08; v,,,(neat)/cm-' 2211 (CN); G,(CDCl,) 1.39-1.80(10H, m), 3.06(3H, s), 3.10-3.18(1 H, m), 3.97-4.03(1 H, m), 5.16-5.24(1 H, m), 5.33-5.42(1 H, m), 6.14(1 H, d, J lo),6.76(2H, d, J 8), 6.89(1 H, t, J 8) and 7.27 (2 H, t, J 8); dc(CDC13) 18.0(q), 26.4(q), 32.5(t), 38.5(t), 38.5(q), 40.6(d), 50.8 (d), 114.5(d, 2C), 116.1(s), 119.0(s), 120.0(d), 127.9(d), 129.3(d, 2C), 129.6(d), 146.2(s) and 147.5(d);m/z 348 (M + 2+, 28), 347 (23), 346 (M+ for 79Br, 30), 345 (18)and 211 (100)(M+, 348.1017.M 348.1024)2-Isomer d: oil; TLC (3 EtOAc in hexane) R, 0.08; G,(CDCl,) 1.39-1.80(10H, m), 3.06 (3H, s), 3.10-3.18(1 H, m), 3.97-4.03(1 H, m), 5.09-5.17(1 H, m), 5.50-5.62(1 H, m), 6.13(1 H, d, J lo),6.76 (2 H, d, J 8), 6.89(1 H, t, J8) and 7.27 (2 H, t, J8); Gc(CDC13) 18.0(q), 26.4 (q), 32.7(t), 38.4(t), 38.5(q), 40.6(d), 50.9(d), 114.5(d, 2C), 116.1(s), 117.1(s), 120.0(d), 127.7(d), 129.3(d, 2C), 129.9(d), 146.2(s) and 147.4(d).8-Bromo-2-(N-methyIanilino)-4-(prop-1-enyf )oct-2-enenitrile 20y. E-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.13; v,,,(neat)/cm-' 2223(CN); GH(CDCL,) 1.45-1.52(4H, m), 1.70 (3H, d, J6), 1.77-1.91 (2 H, m), 3.12(3 H, s), 3.18-3.26(1 H, m), 3.42(2H,t,J6.6),5.32(1H,ddq,J15,7,1.6),5.60(1H,dq,J15, 6), 5.64 (1 H,d, J lo), 6.91-7.03(3 H, m) and 7.30 (2 H, t, J8); Gc(CDCl3) 17.9(q), 25.6(t), 32.4(t), 33.6(t), 34.5(t), 40.0(q), 43.1(d), 114.7(s), 116.6(d), 119.5(d, 2C), 121.1(s), 126.3(d), 129.2(d, 2C), 131.8(d), 135.1(d) and 146.5(s); m/z 348 (M + 2+, 1273,347 (lo), 346(M+ for 79Br,13), 345(8) and 211(100). 2-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.10; ~,,,(neat)/cm-~2210 (CN); G,(CDCl,) 1.30-1.45(4H, m), 1.64 (3H,dd,J6, l), 1.70-1.80(2H,m),3.06(3H,s),3.11-3.18(1H, m), 3.32 (2 H, t, J6.6), 5.21 (1 H, ddq, J 15,7.5, l), 5.39(1 H, dq, J 15,6), 6.13 (1 H,d, J 10),6.77 (2 H,d, J8), 6.89 (1 H, t, J7.5)and 7.27(2H, dd, J 8,7.5); Gc(CDC1,) 17.7(q), 25.6(t), 32.3(t), 33.3 (5), 33.6(t), 38.4(q), 41.0(d), 114.5(d, 2C), 116.2(s), 119.0(s), 120.0(d), 127.5(d), 129.2(d, 2C), 130.0(d), 146.2(s) and 147.8 (d); m/z 348(M + 2+, 26), 347 (25), 346 (M+ for 79Br, 29), 345 (23) and 211(100)(M', 346.1020.M, 346.1045).4-(2-Bromocyclopent-1-enylmethyl)-2-(N-methylaniIino)-hepta-2,5-dienenitrile21y. E-Isomer: yellow oil; TLC (3 EtOAc in hexane) R, 0.21;v,,,(neat)/cm-' 2220 (CN); J. CHEM. SOC. PERKIN TRANS. 1 1992 SH(CDC13) 1.71 (3 H,dd, J6, l), 1.80-2.05 (2 H, m), 2.27-2.71 (6 H, m), 3.1 1 (3 H, s), 3.39-3.56 (1 H, m), 5.41 (1 H, ddq, J 16, 6, l), 5.58 (1 H, dq, J 16,6), 5.66 (1 H, d, J 11 ), 6.94 (2 H, dd, J8, l), 7.01 (1 H, ddd, J 8, 8, 1) and 7.30 (2 H, dd, J 8, 8); G,(CDCI,) 18.0 (q), 22.6 (t), 31.6 (t), 34.2 (t), 35.9 (t), 40.0 (d), 41.6 (q), 114.6 (s), 119.0 (s), 119.7 (d, 2 C), 122.5 (d), 126.2 (d), 129.2 (d, 2 C), 131.6 (d), 134.2 (d), 135.2 (s), 138.4 (s) and 146.5 (s); m/z371 (M + l', 31), 369 (M -13' for 79Br, 30) and 211 (100).Z-Isomer: yellow oil; TLC (3 EtOAc in hexane) R, 0.18; v,,,(neat)/cm-' 2211 (CN); GH(CDCl3) 1.65 (3 H, d, J 6), 1.70-1.93 (2 H, m), 2.09-2.41 (4 H, m), 2.58-2.65 (2 H, m), 3.04 (3 H, s), 3.33-3.46 (1 H, m), 5.30 (1 H, dd, J 15, 7), 5.43(1 H,dq,J15,6),6.20(1H,d,Jll),6.73(2H,dd,J8,1), 6.89 (1 H, ddd, J 8, 8, 1) and 7.30 (2 H, ddd, J 8, 8, 1); Gc(CDCl3) 18.0 (q), 21.5 (t), 34.3 (t), 35.1 (t), 38.6 (t), 39.5 (d), 39.9 (q), 114.4 (d, 2 C), 116.1 (s), 118.3 (s), 119.2 (d), 119.9 (d), 127.2 (d, 2 C), 129.2 (d), 129.9 (s), 137.7 (s), 146.2 (s) and 147.2 (d); m/z371 (M + l', 873, 369 (M -1'1 for 79Br, 7) and 21 1 (100) (M', 370.1048.M, 370.1045). 442-Bromobenzyl)-2-(N-methylanilino)hepta-2,5-dienenitrile 22y. amp;Isomer: yellow oil; TLC (2 EtOAc in hexane) R,0.13; v,,,(neat)/cm-' 2223 (CN); GH(CDCI,) 1.73 (3 H, dd, J 6, l), 2.89-2.94 (2 H, m), 3.04 (3 H, s), 3.70-3.80 (1 H, m), 5.50 (1 H, ddd, J 16, 6, l), 5.57-5.68 (1 H, m), 5.75 (1 H, d, J lo), 6.72 (2 H, dd, J 7, l), 6.98 (1 H, t, J 7), 7.13 (1 H, td, J 7, 2), 7.22-7.32 (4 H, m) and 7.59 (1 H, dd, J8, 1); Gc(CDCl,) 17.9 (q), 39.9 (q), 41.4 (t), 44.0 (d), 114.3 (s), 119.5 (d, 2 C), 121.5 (s), 125.0 (s), 126.0(d), 127.3 (d), 128.0 (d), 129.0(d, 2 C), 131.3 (d), 131.5(d), 132.8 (d), 133.5 (d), 138.3 (s) and 146.4 (s); m/z 382 (M + 2+, 6), 380 (M 'for 79Br, 6) and 21 1 (100).2-Isomer: yellow oil; TLC (2 EtOAc in hexane) Rf 0.09; v,,,(neat)/cm-' 2211 (CN); S,(CDCl,) 1.69 (3 H, d, J 5), 2.69 (3 H, s), 2.78 (1 H, dd, J 14,4.4), 2.97 (1 H, dd, J 14, 5.5), 3.63-3.73 (1 H, m), 5.35-5.51 (2 H, m), 6.28 (1 H, d, J lo), 6.55 (2 H, d, J8), 6.88 (1 H, t, J8), 7.1 1 (2 H, d, J 8), 7.18-7.26 (3 H, m) and 7.52 (1 H, d, J 8); Sc(CDC13) 17.8 (q), 37.7 (q), 41.1 (t), 41.5 (d), 114.4 (d, 2 C), 115.9 (s), 119.4 (s), 119.7 (d), 124.6 (s), 127.2 (d), 127.4 (d), 128.1 (d), 128.9 (d, 2 C), 129.4 (d), 131.3 (d), 132.8 (d), 138.0 (s), 146.0 (s) and 146.3 (d); m/z382 (M + 2'1, 19), 380 (M', 19) and 21 1 (100) (Mf, 380.0885. M, 380.0888).2-(N-Methylanilino)-4-phenylthiohepta-2,5-dienenitrile23y. Z-Isomer: yellow oil; TLC (3 EtOAC in hexane) R, 0.16; v,,,(neat)/cm-' 2212 (CN); a~(CDc1,) 1.69 (3 H, d, J 6), 2.72 (3 H, s), 4.56 (1 H, dd, J 11, 7), 5.48 (1 H, ddd, J 14, 7, l), 5.38-5.57 (1 H, m), 6.21 (1 H, d, J ll), 6.56 (2 H, d, J8), 6.88 (1 H, t, J 8) and 7.18-7.46 (7 H, m); G,(CDCl,) 17.9 (q), 38.2 (q), 48.6 (d), 115.1 (d), 115.7 (s), 119.0 (s), 120.4 (d), 125.7 (d), 128.6 (d), 129.0 (d, 2 C), 129.1 (d, 2 C), 130.1 (d), 132.3 (s), 134.7 (d, 2 C), 141.3 (d) and 145.9 (s); m/z320 (M+, 1) and 21 1 (100). 2-(N-Methylanilino)-6-phenylthiohepta-2,4-dienenitrile23e. E-Isomer: yellow oil; TLC (3 EtOAc in hexane) R,0.11; vmax-(neat)/cm-* 2222 (CN); G,(CDCl,) 1.43 (3 H, d, J 7), 3.16 (3 H, s), 3.88 (1 H, dq, J8.5, 7), 5.74 (1 H, dd, J 15, 8.5), 6.05 (1 H, d, J ll), 6.29 (1 H, dd, J 15, ll), 7.03 (2 H, dd, J7.5, l), 7.09 (1 H, t, J 8) and 7.28-7.42 (7 H, m); Gc(CDC13) 20.3 (q), 40.1 (q), 46.2 (d), 114.3 (s), 117.4 (s), 122.2 (d, 2 C), 123.2 (d), 124.2 (d), 125.7 (d), 127.4 (d), 128.8 (d, 2 C), 129.3 (d, 2 C), 133.0 (d, 2 C), 134.2 (s), 136.9 (d) and 145.8 (s); m/z320 (M+, 1) and 211 (100). 2-Isomer: yellow oil; TLC (3 EtOAc in hexane) R,0.07; v,,,-(neat)/cm-' 2207 (CN); GH(CDCl3) 1.38 (3 H, d, J 7), 2.89 (3 H, s), 3.71 (1 H, dq, J 7.5, 7), 5.88-6.07 (2 H, m), 6.50 (1 H, d, J lo), 6.70 (2 H, d, J 8), 6.87-6.96 (2 H, m) and 7.23-7.41 (6 H, m); G,(CDCl,) 19.6 (q), 3.87 (q), 46.4 (d), 114.9 (d, 2 C), 116.7 (s), 117.5 (s), 120.2 (d), 122.8 (d), 127.7 (d), 128.8 (d, 2 C), 129.2 (d, 2 C), 133.6 (s), 133.7 (d, 2 C), 138.5 (d), 143.3 (d) and 146.0 (s); m/z 320 (M', 2) and 211 (100) (M+, 320.1345.M, 320.1 347). 3091 N-Methyl-N-phenylhexa-2,4-dienamide24u.--Solid, m.p. 73-75 "C; v,,,(KBr)/cm-' 1652 (CO); GH(CDC1,) 1.74 (3 H, d, J 6), 3.32 (3 H, s), 5.68 (1 H, d, J 15), 5.92-6.01 (2 H, m), 7.15 (2 H, d, J7.5), 7.18 (1 H, dd, J 15, lo), 7.32 (1 H, t, J7.5) and 7.38 (2 H, dd, J 7.5); GdCDCl,) 18.5 (q), 37.4 (q), 119.5 (d, 2 C), 127.3 (d), 129.5 (d, 3 C), 130.1 (d), 137.5 (d), 142.1 (d), 143.8 (s) and 166.6 (s); m/z201 (M', SO), 186 (19), 160 (17), 107 (76) and 95 (100) (M', 201.1168. M, 201.1154). 6-Hydroxy-2(N-methylanilino)hepta-2,4-dienenitrile246.-E-Isomer: yellow oil; TLC (30 EtOAc in hexane) R,0.20; vmax-(neat)/cm-' 3397 (OH), 2221 (CN); GH(CDCl,) 1.31 (3 H, d, J 6), 1.59 (1 H, br s, OH), 3.20 (3 H, s), 4.42 (1 H, dq, J 7, 7), 5.83 (1 H, dd, J 15, 7), 6.10 (1 H, d, J ll), 6.59 (1 H, dd, J 15, ll), 7.05-7.13 (3 H, m) and 7.33 (2 H, t, J 8); m/z228 (M', 60), 183 (62) and 171 (100) (M', 228.1266. M, 228.1266).Z-Isomer: yellow solid; m.p. 94-96 "C; TLC (30 EtOAc in hexane) Rf 0.15; v,,,(KBr)/cm-' 3304 (OH), 2205 (CN); amp;,-(CDCI,) 1.23 (3 H, d, J 6), 1.90 (1 H, br s, OH), 3.12 (3 H, s), 4.32(1H,dq,J6,6),6.10(1 H,dd,J15,6),6.41(1H,ddd,J15, 11, l), 6.59 (1 H, d, J ll), 6.80 (2 H, d, J8), 6.90 (1 H, t, J7.4) and 7.27 (2 H, dd, J 8, 7.4); G,(CDCl,) 22.9 (q), 38.8 (q), 67.7 (d), 114.9 (d, 2 C), 116.0 (s), 117.8 (s), 120.2 (d), 121.8 (d), 129.2 (d, 2 C), 138.6 (d), 145.9 (d) and 146.1 (s); m/z228 (M', 63), 183 (60) and 171 (100).5-Hydroxy-2-(N-methylanilino)-4-(prop- 1 -enyl)hept-2-ene- nitrile 25y. An inseparable mixture of isomers (a:b:c:d = 32 :11:9 :48), yellow oil; TLC (1 5 EtOAc in hexane) R, 0.15; v,,,(neat)/cm-' 3469 (OH) and 2213 (CN); G,(CDCl,) inter aka,isomer a, 1.00 (3 H, t, J 7, 7-H), 3.42-3.52 (1 H, m, 5-H), 5.35 (1 H, dd, J 15,7,8-H), 5.67 (1 H, dq, J 15, 6,9-H) and 5.75 (1 H, d, J 10, 3-H); isomer b, 1-01 (3 H, t, J 7) and 5.76 (1 H, d, J 10, 3-H); isomer c, 6.32 (1 H, d, J 10, 3-H); isomer d, 0.88 (3 H, t, J 7), 3.04 (3 H, s, NMe), 3.42-3.52 (1 H, m, 5-H) and 5.27-5.47 (2 H, m, 8-, 9-H; Gc(CDCl,) inter alia, isomer a, 40.4 (4, NMe), 49.8 (d, C-4), 75.1 (d, C-5), 114.6 (s, C-1) and 121.7 (s, C-2); isomer d, 38.2 (q), 47.2 (d), 75.3 (d), 116.1 (s), 120.3 (s) and 144.7 (d); m/z270 (M', 1) and 211 (100) (M', 270.1737.M, 270.1732). 7-Hydroxy-6-methyl-2-(N-methylanilino)nona-2,4-d~enenitrile 256. An inseparable mixture of two 22-isomers (45 :55): yellow oil; TLC (15 EtOAc in hexane) R,0.10 v,,,(neat)/cm-' 3459 (OH) and 2206 (CN); G,(CDCl,) inter alia 6.08 (1 H, dd, J 15, 8, 5-H), 6.25 (1 H, dd, J 15, 10,4-H) and 6.57/6.58 (1 H, d, J 10, 3-H); Gc(CDC13) 9.9/10.2 (9, C-9), 14.3/16.5 (9, C-lo), 27.2/27.6 (t, C-8), 38.6 (9,NMe), 42.9 (d, C-6), 76.4/76.2 (d, C-7), 114.9 (d, 2 C, C-2'), 116.5 (s, C-1), 117.0 (s, C-2), 120.1 (d), 123.9/124.6 (d), 129.2 (d, 2 C, C-3'), 139.1 (d), 146.3/145.4 (d, C-3) and 146.4 (s, C-1'); m/z270 (M+,8) and 211 (100) (M', 270.1737.M, 270.1732). 5-Hydroxy-2-(N-methylanilino)-4-@ropen-1 -yl)oct-2-enenitrile 26y. An inseparable mixture of four isomers (a:b:c:d = 31 :3:9:57), yellow oil; TLC (15 EtOAc in hexane) Rf 0.16; v,,,(neat)/cm-' 3455 (OH) and 2212 (CN); G,(CDCl,) inter alia 2E-isomers (a/b), 0.94 (3 H, t, J 6), 3.12/3.13 (3 H, s), 5.68 (1 H, dq, J 15, 6) and 5.76/5.85 (1 H, d, J 10); 2Z-isomers (c/d), 0.87 (3 H, t, J 7), 3.05/3.04 (3 H, s), 5.27-5.46 (2 H) and 6.33/6.41 (1 H, d, J 10, 3-H); Sc(CDC13) isomers a, 13.9 (q), 18.1 (q), 18.8 (t), 36.7 (t), 40.0 (q), 50.2 (d), 73.7 (d), 114.5 (s), 116.1 (s), 120.1 (d, 2 C), 122.7 (d), 127.9 (d), 128.2 (d, 2 C), 129.4 (d), 130.4 (d) and 146.4 (s); isomer d, 13.8 (q), 18.1 (q), 18.8 (t), 37.2 (t), 38.2 (l), 47.5 (d), 73.4 (d), 114.5 (d, 2 C), 116.0 (s), 119.9 (d), 120.2 (s), 122.7 (d), 129.1 (d, 2 C), 144.8 (d, C-3) and 146.2 (s); m/z284 (M', 10) and 211 (100); (M', 284.1890.M, 284.1885). 7-Hydroxy-6-methyl-2-(N-methylanilino)deca-2,4-dienenitrile 266, Two isomers, yellow oil; TLC (15 in EtOAc in hexane) Rf 0.13; v,,,(neat)/cm-' 3443 (OH) and 2207 (CN); amp;(CDC13) inter alia 0.94/0.92 (3 H, t, J 7, 10-H), 0.99/1.09 (3 H, d, J 7, Me), 6.09/6.10 (1 H, dd, J 15,8.5, 5-H), 6.24/6.26 (1 H, dd, J 15, 10.5) and 6.59/6.60 (1 H, d, J 10.5, 3-H); 6,(CDC13) 14.4/14.0 (4, C-lo), 16.8/16.4 (9, C-11), 19.4/18.8 (t, C-9), 36.5/36.9 (t, C-8), 38.6 (9, NMe), 43.3/43.4 (d, C-6), 74.5/75.1 (d, C-7), 114.9 (d, 2 C, C-2'), 116.4/117.0 (s, CN), 120.1 (d), 121.7 (s), 124.6 (d), 129.2 (d, 2 C, C-3'), 139.1 (d), 140.1 (s, C-1') and 145.4/146.3(d, C-3); m/z284 (M+, 973,212 (23) and 211 (100).7-H~droxy-6-methyl-7-phenyl-2-(N-methylanilino)hepta-2,4-dienenitrile 27~.Z-isomer a: yellow oil; TLC (20 EtOAc in hexane) R, 0.15; 6,(CDC13) inter alia, 0.88 (3 H, d, J 7), 3.08 (3 H, s), 4.44 (1 H, d, J7, 7-H), 6.14 (1 H, dd, J 15, 7.5, 5-H), 6.26 (1 H, dd, J 15, 10,4-H) and 6.59 (1 H, d, J 10, 3-H); G,(CDCI,) 16.5 (q), 38.6 (q), 45.1 (d), 76.0 (d), 116.6 (s), 116.9 (s, C-2) and 145.4 (d, C-3). 2-Isomer b: yellow oil; TLC (20 EtOAc in hexane) R, 0.17; v,,,(neat)/cm-' 3427 (OH) and 2207 (CN); 6,(CDC13) inter alia,1.01 (3 H, d, J 7), 3.02 (3 H, s), 4.55 (1 H, J6), 5.85 (1 H, dd, J 15,8.5), 6.14 (1 H, dd, J 15, 10) and 6.50 (1 H, d, J 10); G,(CDCl,) inter alia, 14.8 (q), 38.7 (q), 44.5 (d), 77.5 (d), 116.6 (s), 116.9 (s) and 145.2 (d); m/z318 (M', 4) and 211 (100) (M', 318.1737.M, 318.1732). 7-Hydroxy-6-methyl-2-(N-methylanilino)deca-2,4,8-triene-nitrile 2. An inseparable mixture of two 22-isomers (55:45), yellow oil; TLC (15 EtOAc in hexane) R, 0.13; 6,(CDCl,) inter alia,0.96/0.95 (3 H, d, J 7), 1.68 (3 H, d, J 7), 3.12 (3 H, s), 3.92/3.83 (1 H, dd, J6,6), 5.38/5.40 (1 H, dd, J 15, 6), 5.62-5.74 (1 H, m), 6.09 (1 H, dd, J 15.5, 8), 6.25/6.27 (1 H, dd, J 15.5, 10, 4-H) and 6.58/6.60 (1 H, d, J 10, 3-H); S,(CDCl,) inter alia 14.9/16.0(q), 17.6/17.7(q), 38.6 (q), 43.0/43.5 (d, C-6), 77.0/76.3 (d, C-7), 116.4 (s), 117.0 (s) and 145.1/145.8 (d, C-3); m/z282 (M+, 3) and 211 (100) (M+, 282.1725.M, 282.1732). J. CHEM. SOC. PERKIN TRANS. I 1992 122.6 (s), 123.1(d, 2 C), 124.8 (d), 127.0(d), 127.6 (d), 127.8 (d, 3 C), 128.3 (d, 2 C), 129.3 (d, 2 C), 137.9 (s) and 145.6 (s); m/z304 (M+, 979, 213 (79), 197 (60), 183 (31) and 169 (100). (2Z,42)- Isomer: yellow oil; TLC (5 EtOAc in hexane) R, 0.1 1; v,,,-(neat)/cm-' 2208 (CN); SH(CDC1,) 3.13 (3 H, s), 4.21 (2 H, dd, J 6, 1.6), 4.54 (2 H, s), 5.88 (1 H, dtd, J 11, 6, 1), 6.31 (1 H, ddd, J 10, 11, 1.6), 6.80 (2 H, d, J 8), 6.90-6.94 (2 H, m) and 7.21-7.38 (7 H, m); G,(CDCl,) 38.9 (q), 66.1 (t), 72.7 (t), 115.2 (d, 2 C), 119.0 (s), 120.4 (d), 122.6 (s), 123.6 (d), 127.6 (d), 127.9 (d, 2 C), 128.5 (d, 2 C), 129.2 (d, 2 C), 132.7 (d), 135.4 (d), 137.5 (s) and 145.9 (s); m/z304 (M+, 18), 213 (83, 197 (57), 183 (29) and 169 (100 (M+, 304.1580.M, 304.1576). Ethyl 6-cyano-6-(N-methylanilino)hexa-3,5-dienoate33. E-Isomer: yellow oil; TLC (10 EtOAc in hexane) R, 0.14; v,,,(neat)/cm-' 2228 (CN); d~(cDcI3) 1.27 (3 H, t, J 7), 3.16- 3.23 (2 H, m), 3.20 (3 H, s), 4.16 (2 H, q, J7), 5.89 (1 H, dt, J 15, 7), 6.15 (1 H, d, J ll), 6.53 (1 H, ddt, J 15, 11, l), 7.04-7.14 (3 H, m) and 7.28-7.38 (2 H, m); S,(CDCl,) 14.1 (q), 38.2 (t), 40.1 (q), 60.8 (t), 114.3 (s), 121.1 (s), 122.4 (d, 2 C), 122.9 (d), 124.2 (d), 127.1 (d), 129.1 (d), 129.2 (d, 2 C), 145.8 (s) and 171.1 (s); m/z270 (M +,5779,269 (49) and 197 (100).Z-Isomer: oil; TLC (10 EtOAc in hexane) R, 0.12; v,,,-(neat)/cm-1 2212 (CN); S,(CDC13) 1.24 (3 H, t, J 7), 3.13 (3 H, s), 3.15 (2 H, d, J 7), 4.14 (2 H, q, J 7), 6.20 (1 H, dt, J 15, 7), 6.32 (1 H, dd, J 15, lo), 6.63 (1 H, d, J lo), 6.80 (2 H, dd, J8, l), 6.91 (1 H, ddd, J 8, 8, 1) and 7.28 (2 H, ddd, J 8, 8, 1); 6,-(CDCl,) 14.0 (q), 38.2 (t), 38.7 (l), 60.9 (t), 114.8 (d, 2 C), 116.6 (s), 117.5 (s), 120.2 (d), 126.6 (d), 129.2 (d 2 C), 134.2 (d), 138.5 (d), 146.1 (s) and 170.2 (s); m/z270 (M+, 5779, 269 (46) and 197 (100) (M', 270.1371. M, 270.1368). 7-Hydroxy-6-methyl-2-(N-methylanilino)-9-phenylnona-2,4,8-trienenitrile 29c. An inseparable mixture of two 22-isomers (45:55), yellow oil; TLC (15 EtOAc in hexane) R, 0.13; v,,,(neat)/cm-' 3435 (OH) and 2206 (CN); G,(CDCl,) inter alia,1.04/1.05 (3 H, d, J7), 3.10/3.11 (3 H, s), 4.10/4.18 (1 H, t, J 7), 6.32/6.26 (1 H, dd, J 15, 7) and 6.60/6.55 (1 H, d, J 11); S,(CDCl,) inter alia, 14.9/16.1 (q), 38.6 (q), 43.7/43.3 (d), 76.3/75.9 (d), 116.6 (s), 117.0 (s) and 145.1 (d); m/z344 (M+, 0.1) and 211 (100) (M', 344.1879.M, 344.1888). 2-(N-Methylanilino)-6-phenylhexa-2,4-dienenitrile30.E-Iso-mer: yellow oil; TLC (3 EtOAc in hexane) R, 0.18; v,,,-(neat)/cm-' 2224 (CN); GH(CDC1,) 3.18 (3 H, s), 3.51 (2 H, d, J 7), 5.96 (1 H, dt, J 15, 7), 6.20 (1 H, d, J ll), 6.50 (1 H, dt, J 15, 11) and 7.03-7.35 (10 H, m); G,(CDCl,) 39.4 (t), 40.0 (q), 114.7 (s), 120.1 (s), 121.6 (d, 2 C), 122.4 (d), 124.3 (d), 125.6 (d), 126.3 (d), 126.7 (d), 128.4 (d, 2 C), 128.5 (d, 2 C), 129.2 (d, 2 C), 136.0 (d), 139.5 (s) and 146.0(s); m/z274 (M+,81) and 273 (100).Z-Isomer: yellow oil; TLC (3 EtOAc in hexane) Rf 0.14; v,,,(neat)/cm-' 2209 (CN); SH(CDC1J 3.12 (3 H, s), 3.44 (2 H, d, J6), 6.17 (1 H, dt, J 16,6), 6.22 (1 H, dd, J 16, ll), 6.60 (1 H, d, J 1 l), 6.78 (2 H, dd, J 7, l), 6.91 (1 H, t, J 7), 7.07 (2 H, t, J 7) and 7.20-7.35 (5 H, m); m/z274 (M', 78) and 273 (100). 2-(N-Methylanilino)-6-phenylthiohexa-2,4-dienenitrile31. E-Isomer: yellow oil; TLC (3 EtOAc in hexane) R,0.17; vmax-(neat)/cm-' 2225 (CN); GH(CDC1,) 3.15 (3 H, s), 3.63 (2 H, d, J 7.9, 5.79 (1 H, dt, J 15, 73, 6.04 (1 H, d, J ll), 6.48 (1 H, dd, J 15, 11) and 7.01-7.35 (10 H, m); Gc(CDC13) 36.9 (t), 40.1 (q), 114.2 (s), 121.1 (s), 122.2 (d), 122.5 (d, 2 C), 124.3 (d), 126.4 (d), 128.4 (d), 128.8 (d, 2 C), 129.2 (d, 2 C), 130.1 (d, 2 C), 130.4 (d), 135.4 (s) and 145.7 (s); m/z306 (M', 44), 262 (8), 248 (10) and 197 (100) (M+, 306.1190.M, 306.1191). 6-Benzyloxy-2-(N-methylanilino)hexa-2,4-dienenitrile32.(2E, 42)-Isomer: yellow oil; TLC (5 EtOAc in hexane) Rf0.13; v,,,(neat)/cm-' 2212 (CN); GH(CDC13) 3.15 (3 H, s), 4.15 (2 H, d, J 6.6), 4.51 (2 H, s), 5.71 (1 H, dt, J 11, 6.6), 6.30 (1 H, d, J 12),6.59(1 H,dd,Jl2,11),7.07-7.17(3H,m)and7.22-7.37(7 H, m); G,(CDCl,) 40.3 (q), 65.9 (t), 72.2 (t), 114.0 (s), 116.0 (d), 4-(2-Bromobenzy1)-2-(N-methylanilino)-6-phenylhexa-2,4-di-enenitrile 34y.E-Isomer: yellow oil; TLC (2 EtOAc in hex- ane) R, 0.17; v,,,(neat)/cm-' 2212 (CN); G,(CDCl,) 3.01 (1 H, dd, J 13,9), 3.07 (3 H, s), 3.18 (1 H, dd, J 13, 7), 3.85-4.01 (1 H, m), 5.74 (1 H, d, J ll), 6.22 (1 H, dd, J 16, 7), 6.51 (1 H, d, J 16), 6.76 (2 H, dd, J 8, l), 7.00 (1 H, td, J 7, l), 7.12-7.40 (11 H, m) and 7.59 (1 H, dd, J 8, 1); G,(CDCI,) 40.1 (q), 41.5 (t), 44.6 (d), 114.3 (s), 120.3 (d, 2 C), 122.2 (s), 122.9 (d), 125.1 (s), 126.3 (d, 2 C), 127.5 (d), 127.6 (d), 128.2 (d), 128.6 (d, 2 C), 129.2 (d, 2 C), 130.0 (d), 130.8 (d), 130.9 (d), 131.6(d), 133.0(d), 136.9 (s), 138.1 (s) and 146.4 (s); m/z444 (M + 2+, 1279,443 (56), 442 (M+ for 79Br, 11), 441 (59, 354 (59, 352 (17) and 273 (100). Z-Isomer: yellow oil; TLC (2 EtOAc in hexane) R, 0.14; v,,,(neat)/cm-' 2223 (CN); G,(CDCl,) 3.08 (1 H, dd, J 13, 7), 3.17(3H,s),3.24(1 H,dd,J13,8),3.7amp;3.85(1 H,m),6.06(1H, dd, J 1 5,7), 6.1 5 (1 H, d, J 1 1 ), 6.36 (1 H, d, J 15), 7.00-7.38 (14 H, m) and 7.53 (1 H, dd, J8,l); G,(CDCl,) 42.6 (q),45.3 (t),49.2 (d), 119.7 (d), 120.3 (s), 120.3 (s), 121.7 (d, 2 C), 123.8 (d), 124.8 (s), 125.4 (d), 125.9 (d), 126.6 (d), 127.0(d), 127.6(d, 2 C), 128.6 (d, 2 C), 129.2 (d), 129.3 (d, 2 C), 131.5 (d), 132.8 (d), 138.2 (s), 139.1 (s), 143.0 (d) and 146.0 (s); m/z444(M + 23 +,14), 443 (53), 442 (M' for 79Br, 17), 441 (54) and 273 (100) (M+,442.1048.M, 442.1045). 4-(2-Bromobenzyl)-2-(N-methylanilino)-6-phenylthiohexa-2,5-dienenitrile 35y. E-Isomer: yellow oil; TLC (4 EtOAc in hexane) R, 0.08; v,,,(neat)/cm-' 2226 (CN); GH(CDCl3) 3.07 (3 H, s), 2.95 (1 H, dd, J 13, 8), 3.08 (1 H, dd, J 13, 7), 3.78-3.96 (1 H, m), 5.58 (1 H, d, J lo), 5.87 (1 H, dd, J 15, 7.6), 6.25 (1 H, dd, J 15, l), 6.79 (2 H, dd, J 8, l), 7.02 (1 H, td, J 7.5, l), 7.11-7.30 (10 H, m) and 7.58 (1 H, dd, J 8, 1); G,(CDCl,) 40.1 (q), 41.4 (t), 44.7 (d), 114.1 (s), 120.8 (d, 2 C), 122.5 (s), 123.2 (d), 124.2 (d), 125.1 (s), 126.6 (d), 127.5 (d), 128.3 (d), 128.6 (d), 129.0(d, 2 C), 129.2 (d, 2 C), 129.3 (d, 2 C), 131.6 (d), 133.0 (d), 133.8 (d), 135.1 (s), 137.8 (s) and 146.2 (s); m/z4.75 (M + 11' for 79Br, 0.1) and 305 (100) (M +,474.0776.M, 474.0766). 6-BenzyZoxy-4-(2-bromobenzyl)-2-(N-methylanilino)hexa-2,5-dienenitrile 36y.(22,5E)-Tsomer:yellow oil; TLC (10 EtOAc in hexane) Rf0.21; v,,,(neat)/cm-' 221 1 (CN); G,(CDCl,) 2.63 J. CHEM. SOC. PERKIN TRANS. I 1992 (3 H, s), 2.62-3.00 (2 H, m), 3.52-3.62(1 H,m), 4.69 (2 H,s), 4.78(1 H, dd, J 13,9), 6.16 (1 H,d, J 13), 6.23(1 H, d, J lo),6.53(2H, dd, J 8, l), 6.84(1 H, td, J 8, l), 7.04-7.36(10H,m) and 7.50(1 H,d, J 8); Gc(CDC13)37.7(q), 37.8(d), 42.2(t), 71.4 (t), 103.8(d), 114.5(d, 2 C), 116.1(s), 119.0(s), 119.9(d), 124.7 (s), 127.4(d), 127.5(d, 2 C), 128.0(d), 128.3(d), 128.5(d, 2 C), 129.1(d, 2 C), 131.5 (d), 133.0(d), 136.6(s), 138.0(s), 146.0(s), 146.6(d) and 148.0(d);m/z473(M + 11 'of 79Br,3), 471 (4), 303 (68)and 91 (100). (22,5Z)-Isomer: yellow oil; TLC (10 EtOAc in hexane) R, 0.19; v,,,(neat)/cm-' 2211 (CN); G,(CDCI,) 2.74(3 H,s), 2.88 (2 H, dd, J8,4), 4.10-4.27 (1 H,m), 4.33(1 H,dd, J9,6), 6.07 (1 H,d, J6), 6.33 (1 H,d, J lo), 6.52 (2 H,dd,J8,1),6.82(1H,td,J7,1),7.07-7.32(10H,m)and7.47(1 H, dd, J 8,1); GC(CDCI3) 34.6(d), 38.0(q), 40.9(t), 73.9(t), 105.1 (d), 114.4(d, 2 C), 116.3(s), 119.0(s), 119.5(d), 124.8(s), 127.2 (d), 127.3(d, 2 C), 127.9(d), 128.0(d), 128.4(d, 2 C), 129.0(d, 2 C), 131.4(d), 132.8(d), 137.0(s), 138.2(s), 146.3(s), 146.4(d)and 147.3(d);m/z 473(M + 11' of 79Br, 573,471 (6), 303 (65)and 91 (100) (M+,472.1156. N,472.1151).4-(2-Benzyloxyvinyl)-7-iodo-2-(N-methylanilino)hept-2-ene-nitrile 37y. (2Z,SZ)-Isomer: yellow oil; TLC (5 EtOAc in hexane) R, 0.15; v,,,(neat)/cm-' 2211 (CN); G,(CDCl,) 1.42-1.55 (2H,m), 1.67-1.81 (2 H, m), 3.00(3 H, s), 3.08 (2 H,t, J 7), 3.65-3.82(1 H, m), 4.19(1 H, dd, J9, 6), 4.70 (2 H,s), 6.11(1H,d, J6), 6.15 (1 H,dd, J 10,l), 6.76 (2 H, dd, J8,l), 6.88(1H,td, J 8, 1) and 7.18-7.34 (7 H,m); Gc(CDC13) 6.1(t), 30.8(t), 32.6(d), 35.3 (t), 38.4(q), 74.1(t), 105.5(d), 114.5(d, 2 C), 116.3 (s), 118.8(s), 119.8(d), 127.5(d, 2 C), 128.1(d), 128.5(d, 2 C), 129.2(d, 2 C), 136.9(s), 146.4(s), 146.5(d) and 147.8(d); m/z 472 (M+, 25), 443 (22), 381 (16), 303 (68), 211 (12), 145 (17) and 91 (100);(M',472.0998.M, 472.1013).Ethyl7-cyano-7-(N-methylanilino)hepta-4,6-diene-3-carboxyl-ate 38a. E-Isomer: yellow oil, TLC (15 EtOAc in hexane) R, 0.18;v,,,(neat)/cm-' 2222 (CN); SH(CDC13) 0.94(3 H, t, J 7), 1.29 (3 H, t, J 7), 1.7s1.95 (2 H, m), 2.81-3.12 (1 H),3.22 (3 H,s), 4.16 (2 H,q, J7), 5.81 (1 H,dd, J 15,7), 6.13(1 H, d, J 1 l), 6.53(1 H, dd, J 15,1 l), 7.05-7.18(3 H, m) and 7.23-7.35 (2 H,m).2-Isomer: yellow oil, TLC (15 EtOAc in hexane) Rf0.18; GH(CDC1,) 0.86(3 H,t, J 7), 1.23 (3 H,t, J 7), 1.50-1.70 (2 H, m), 2.81-3.12(1 H,m), 3.15 (3 H,s), 4.11(2 H,q, J7), 6.10 (1H,dd, J 15, 7), 6.32 (1 H,dd, J 15, ll), 6.61(1 H,d, J ll), 6.72 (2 H,d, J 7.9, 6.91 (1 H,t, J 7.5) and 7.27 (2 H,t, J 7.5); m/z 298 (M', 34), 269 (16) and 225 (100)(M', 298.1676.M, 298.1681).Ethyl 7-cyano-3-ethyl-7-(N-methylanilino)hepta-4,6-diene-3-carboxylate 39~.E-Isomer: yellow oil; TLC (15 EtOAc in hexane) Rf 0.24;v,,,(neat)/cm-' 2228 (CN); d~(cDCl3)0.83(6H,t, J 7), 1.26 (3 H,t, J 7), 1.60-1.80 (4H, m), 3.22(3 H,s), 4.19 (2H,q, J7), 6.05 (1 H, d J 15), 6.26(1 H,d, J lo), 6.48(1 H,dd, J 15,lo), 7.03-7.13(3 H,m) and 7.27-7.40 (2 H,m).2-Isomer: yellow oil; TLC (15 EtOAc in hexane) R, 0.24; G,(CDCI,): 0.73(6 H,t, J 7), 1.24 (3 H, t, J 7), 1.50-1.73 (4H, m), 3.17(3 H, s), 4.15(2 H,q, J7), 6.25 (1 H,d, J 15, 3-H),6.28 (1 H, dd, J 1 5, lo), 6.62(1 H, d, J lo), 6.82 (2 H, dd, J 8,1), 6.90 (1 H, td, J 8, 1) and 7.27 (2 H, td, J 8, l), m/z326 (M', 27), 297 (38)and 253 (100)(M', 326.1986.M,326.1994). Ethyl 8-cyano-3-hydroxy-8-(N-methylanilino)octa-5,7-diene-4-carboxylate 40~.Two isomers, threolerythro = 64:36. 2-threo-Isomer: yellow oil; TLC (20 EtOAc in hexane) R, 0.12; v,,,(neat)/cm-' 3479 (OH), 2210 (CN) and 1727 (CO); S"(CDCl3) 0.89(3 H,t, J 7), 1.23 (3 H,t, J 7 H),1.25-1.50 (2 H, m), 2.69(1 H, br, J 4, OH), 3.07(1 H, dd, J 9,4), 3.16(3 H,s), 3.80-3.92(1 H,m), 4.14 (2 H,q, J7), 6.19 (1 H,dd, J 15,9), 6.35 (1 H,dd, J 15,lo), 6.59(1 H,d, J lo), 6.83(2 H,dd, J8,l), 6.91(1 Kt4J7.5, l)and7.28(2H,dd,J8,7.5);Gc(CDC13)9.9(q),14.0 (91, 27.2(0,38.8(q), 54.3(d), 61.3(t), 73.1(d), 115.2(d, 2 C), 117.9(s), 120.4(d), 127.0(s), 128.1 (d), 129.3(d, 2 C), 135.1 (d), 137.3(d), 146.2(s) and 172.5(s);m/z328(M+,373,270(53), 241 (28)and 224 (100).2-erythro-Isomer: yellow oil, TLC (20 EtOAc in hexane) R, 0.10;v,,,(neat)/cm-' 3494 (OH),2224 (CN) and 1726 (CO); amp;(CDC13) 0.97(3 H, t, J 7), 1.29 (3 H, t, J 7), 1.36-1.55 (2 H, m),2.54(1 H, dd, J 11, 7), 3.21 (3 H,s), 3.70-3.76(1 H,m),4.19 (2 H,q, J 7), 5.81 (1 H, dd, J 15, ll), 5.98(1 H,dd, J 15, ll), 6.55(1 H, d, J ll), 6.83 (2 H, dd, J8,l), 6.92(1 H,td, J7.5,1) and 7.29 (2 H,dd, J8, 7.5); Gc(CDC13)9.7(q), 14.1(q), 27.7(t), 40.2 (q), 55.5 (d), 61.2(t), 73.8 (d), 115.3 (d, 2 C), 116.8 (s), 121.7(d), 122.2(s), 127.2(d), 129.3(d, 2 C), 136.1(d), 137.0(d), 145.7(s) and 173.0(s); m/z328 (M', 379,270 (37), 241 (26) and 224 (100)(M+, 328.1783.M 328.1787).5-Ethyl-4-prop-1 -enyl-4,5-dihydrofuran-2(3H)-one41. trans-Isomer: yellow oil; TLC (10 EtOAc in hexane) R, 0.28; v,,,(neat)/cm-' 1779 (CO); GH(CDC13) 0.99(3 H, t, J 7), 1.50- 1.81(2H, m), 1.65(3 H,dd, J6,l), 2.36(1 H, dd, J 17, lo), 2.61 (1 H, dd, J 17, 8), 2.59-2.76 (1 H,m),4.00(1 H, td, J8,4), 5.29 (1 H, ddq, J 15,8, 1) and 5.56(1 H, dq, J 15,6);S,(CDCI3) 10.0 (9).17.8(q), 26.4(t), 36.0(t), 45.0(d), 86.4(d), 128.6 (d), 128.9 (d) and 176.1 (s); m/z155 (M + lJ+,2), 97 (12) and 69 (100). cis-Isomer: yellow oil, TLC (10 EtOAc in hexane) Rf 0.23;v,,,(neat)/cm-' 1768 (CO); dH(CDC1,) 0.95 (3 H, t, J 7), 1.44-1.63(2 H,m), 1.66(3 H, dd, J6,l), 2.34(1 H, dd, J 17,6), 2.63(1 H,dd, J 17, 8), 3.03-3.12 (1 H,m), 4.31-4.44 (1 H,m), 5.32(1 H,ddq, J 15,6, 1)and 5.54(1 H, dq, J 15,6); Gc(CDC13) 10.0(q), 17.8(q), 23.9 (t), 35.2(t), 42.0(d), 85.0(d), 126.6(d), 128.8(d) and 176.6(s); m/z 154(M+,3),97 (11) and 69 (100) (M', 154.1009.M, 154.0993). 4-Prop-1-enyl-5-propyl-4,5-dihydrofiran-2(3H)-one42. trans-Isomer: yellow oil; TLC (10 EtOAc in hexane) R, 0.29; v,,,(neat)/cm-' 1772 (CO); GH(CDCl3) 0.89(3 H, t, J 6), 1.31-1.66(4 H, m), 1.64(3 H, dd, J6, 1.6), 2.34 (1 H, dd, J 16.6,lo),2.58(1 H,dd, J 16.6, 8), 2.62-2.73 (1 H, m), 4.04(1 H, td, J 8, 3.9,5.27 (1 H, ddq, J 15, 8, 1.6) and 5.55 (1 H, dq, J 15, 6); Gc(CDCl3) 13.7(q), 17.8(q), 19.0(t), 35.5 (t), 35.8(t), 45.5 (d), 85.0(d), 128.5(d), 128.9(d) and 176.2(s); m/z169 (M + 1+, 373, 97 (13) and 69 (100).cidsomer: yellow oil, TLC (10 EtOAc in hexane) Rf 0.24; v,,,(neat)/cm-' 1772 (CO); GH(CDCl3)0.89(3 H, t, J 7), 1.27-1.55 (4 H, m), 1.66(3 H, dd, J6, 1.4), 2.33 (1 H,dd, J 17,6), 2.62 (1 H, dd, J 17,8), 3.01-3.31 (1 H, m), 4.39-4.50(1 H,m), 5.32(1 H,ddq, J 15,9,1.4)and 5.52 (1 H,dq, J 15, 6);Gc(CDC13, 75 MHz)13.7(q), 13.8 (q),18.9(t), 32.8(t), 35.1 (t), 42.1 (d), 83.4(d), 126.7(d), 128.8 (d) and 176.6 (s); m/z169 (M +l', 3), 97 (12) and 69 (100) (M', 168.1146.M, 168.1150).Acknowledgements We are grateful to the National Science Council of the Republic of China for financial support (Grant NSC8 1-0208-M002-20). References 1 For reviews, see (a) D. Seebach, Synthesis, 1969, 17; (b) B.-T. Grobel and D. Seebach, Synthesis, 1977, 357; (c) J. D. Albright, Terrahedron,1983,39,3207. For heteroatom- and cyano-substituted carbanions, see (d) J. F. Biellmann and J. B. Ducep, Org. Reacr. (N.Y.), 1982, 27, 1; (e) S. Arseniyadis, K. S. Kyler and D. S. Watt, Org. React. (N.Y.), 1984,31, 1. 2 (a) V. Hertenstein, S. Hunig and M. Oller, Synthesis, 1976, 416; (b) V. Hertenstein, S.Hunig and M.Oller, Chem. Ber., 1980,113,3783. 3 (a)F. E. Ziegler and C. C. Tam, J. Org. Chem., 1979,44,3428; (b) E. Dziadulewicz, D. Hodgson and T. Gallagher, J. Chem. Soc., Perkin Trans. I, 1988,3367; (c) K.Takahashi, A. Honma, K. Ogura and H. Iida, Chem. Leti., 1982, 1263; (d) H.Ahlbrecht and C. Vonderheid, Synthesis, 1975, 512; (e) L. Ghosez, M.Chantrenne, J. Toye and B. Lesur, Tetrahedron Lett., 1979, 20, 2835; (f)V. Reutrakul, P. Ratananukul and S. Nimgirawath, Chem. Lett., 1980, 71; (g)J. M. Fang, L. F. Liao and C. C. Yang, J. Chin. Chem. Soc. (Taipei),1985, 9, 1. 4 For reviews, see (a) H. Yasuda and A. Nakamura, J. Organomet. Chem., 1985,285, 15; (b) R. D. Ernst, Ace. Chem. Res., 1985,18, 56. 5 (a) K.Maruyarna, N. Nagai and Y. Naruta, Chem. Lett., 1987, 97; (h) Y. Naruta, Y. Nishigaichi and K. Maruyama, J. Org. Chem., 1988, 53, 1192; (c) R. Yamaguchi, T. Hamasaki, T. Sasaki, S. Kozima and H. Takaya, Synlett, 1991, 719; (d) Y. Naruta, Y. Nishigaichi and K. Maruyama, J. Urg. Chem., 1991,56,2011. 6 K. Fisher and S. Hunig, Chem. Ber., 1986,119,2590. 7 (a) D. Seebach, M. Kolb and B.-T. Grobel, Angew. Chem., Znt. Ed. Engl., 1973, 12,69; (b) D. Seebach and M. Kolb, Justus Liebigs Ann. Chem., 1977, 811; (c) M. Y. Chen, Ph. D. Thesis, National Taiwan University, 1991. 8 (a) S. Florio, L. Ronzini and S. Sgarra, Tetrahedron Lett., 1990, 31, 2327; (b) E. Epifani, S. Florio, G. Ingrosso, L. Ronzini, R. Sgarra and L. Troisi, Tetrahedron, 1991,47,7489. 9 J. M. Fang, C. C. Yangand Y. W. Wang, J.Org. Chem., 1989,54,477. 10 (a) B. Costisella and H. Gross, Tetrahedron, 1982, 38, 139; (b) N. Stevenart-De Mesmaeker, R. Merenyi and H. G. Viehe, Tetrahedron Lett., 1987,28,2591. 11 (a) D. S. Watt, J. Org. Chem., 1974, 39, 2799; (6) T. H. Chuang, C. C. Yang, C. J. Chang and J. M. Fang, Synlett, 1990,733. 12 (a) R. B. Bates, D. W. Gosselink and J. A. Kaczynski, Tetrahedron Lett., 1967, 205; (b)G. J. Heiszwolf and H. Kloosterziel, Reel. Trav. Chim. Pays-Bas, 1967, 86, 1345; (c) M. Schlosser and G. Rauchschwalbe, J. Am. Chem. SOC.,1978,100,3258; (4H. Yasuda, Y. Ohnuma, M. Yamauchi, H. Tani and A. Nakamura, Bull. Chem. SOC.Jpn., 1979, 52, 2036; (e) H. Bosshardt and M. Schlosser, Heh. Chim. Acta, 1980,63,2393. J. CHEM. SOC. PERKIN TRANS. 1 1992 13 (a)J. J. Fitt and H. W. Gschwend, J. Org. Chem., 1979, 44, 303; (b) Y. Naruta, Y. Nishigaichi and K. Maruyama, Chem. Lett., 1988,135. 14 J. M. Fang and C. J. Chang, J. Chem. SOC.,Chem. Commun., 1989, 1787. 15 (a)T. Laube, J. D. Dunitz and D. Seebach, Helv. Chim. Ada, 1985, 68, 1373; (b) R. Shirai, M. Tanaka and K. Koga, J. Am. Chem. Soc., 1986, 108, 543; (c) J. S. DePue and D. B. Collum, J. Am. Chem. Soc., 1988,110,5524. 16 T. Mukaiyama, H. Hayashi, T. Miwa and K. Narasaka, Chem. Lett., 1982, 1637. 17 G. Cainelli, G. Cardillo, M. Contento, P. Grasselli and A. U. Ronchi, Guzz. Chim. Ztul., 1973, 103, 117. 18 J. M. Fang, H. T. Chang and C. C. Lin, J. Chem. Soc., Chem. Commun., 1988,1385. 19 T. Rajamannar and K. K. Balasubramanian, Tetrahedron Lett., 1988,29,5789. 20 J. M. Fang and C. C. Chen, J. Chem. Soc., Perkin Trans. I, 1990, 3365. 21 (a) E. L. Eliel, V. G. Badding and M. N. Rerick, J. Am. Chem. SOC., 1962, 84, 2371; (b) S. Danishefsky and J. Regan, Tetrahedron Lett., 1981,33,3919. 22 (a) G. 0.Schenck and R. Steinmetz, Chem. Ber., 1963, 668, 20; (6) J. H. Sheu, C. F. Yen, H. C. Huang and Y. L. V. Hong, J. Org. Chem., 1989,54,5126. Paper 2/03496D Received 2nd July 1992 Accepted 14th August 1992