J. CHEM. SOC. PERKIN TRANS. I 1985 Structures of the Cephalosporolides B-F, A Group of C,, Lactones from Cephalosporiurnaphidicofa Mark J. Ackland, James R. Hanson," and Peter 9. Hitchcock School of Molecular Sciences, University of Sussex, Brighton, Sussex BN 7 9QJ Arnold H. Ratcliffe I.C.I. Pharmaceuticals Division, Alderley Park, Macclesfield, Cheshire SK 70 4TG The structures of the pentaketides lactones, the cephalosporolides B-F, combination of spectroscopic, chemical, and X-ray analyses. were elucidated by a The fungus, Cephalosporium aphidicola, produces the diter- penoid, aphidicolin (1)' In the course of our biosynthetic studies on aphidicolin2 we have elucidated the structures of a number of other metabolites of the fungus including a bisdeca- nolide, thiobiscephalosporolide A (2).3In this paper we report the structures of a group of lactones, the cephalosporolides B-F, (3),(4) and (7)-49)which were produced by an industrial fermentation of the fungus C. aphidicola, ACC 3490.These compounds are related to the recently described diplodialides e.g. (l0)J produced by Diplodia ~inea,~ and the pyrenolides e.g.(1 l) produced by Pyrenophora terex5 Cephalosporolide B, CI0Hl4O4,M+ 198 (3) showed i.r. absorptions at 3 320 cm-' (OH), 1 730 and 1 260 cm-' (COO), 1690 and 1640 cm-' (ap-unsaturated ketone) and U.V. absorption at 215 nm (E 5080). The I3C n.m.r. spectrum (see Table 1) contained ten resonances which, on the basis of their chemical shift and multiplicity in the SFORD spectrum, were assigned to one methyl group, three methylenes, two CH-0 Froups, one -CH=CH-, one COO and one c--O grouping.The H n.m.r. spectrum (see Table 2) confirmed the presence of the methyl group 6 1.25 (d, J 6.5 Hz),a secondary lactone (6 5.05), a low-field secondary alcohol (65.25) and an ap-unsaturated ketone (65.80 and 6.23). 'H N.m.r. spin decoupling studies (for coupling constants see Table 3), established several part structures.. Irradiation of the methyl group doublet (6 1.25) converted the multiplet resonances at 6 5.05 into a double doublet (J 4 and 7 Hz).Irradiation at 6 5.05 collapsed the methyl doublet to a singlet and modified a two-proton multi- plet (6 2.05) suggesting the presence of the part structure (12).The key to a second part structure came from the irradiation of a double doublet at 6 2.95 (J 6 and 15 Hz). This led to the collapse of a multiplet at 6 5.22 to a broadened triplet (J9 Hz) and to perturbation of a multiplet at 62.45. Irradiation at 6 5.22 not only collapsed the double doublet at 6 2.95 to a doublet (J 15 Hz) and modified the three-proton multiplet at 6 2.45, but also reduced the double doublet at 6 5.8 (J 9 and 12 Hz) to a doublet (J 12 Hz). Irradiation at 6 5.8 confirmed the coupling to the resonance at 6 5.22 and to the second olefinic proton resonance at 66.23 (J12Hz).These 'H decoupling experiments were best accommodated by part structure (13) and suggested the overall structure, 3-hydroxy-6-oxodec-4-en-9-olide(3) for the metabolite. This structure was confirmed by inter-relation- ship with thiobiscephalosporolide-A(uide infra).Spectroscopic information concerning the configuration of the double bond was ambiguous. The magnitude of the olefinic coupling con- stant lies between the commonly accepted6 ranges for cis-and trans-olefins. Consequently an X-ray analysis (see Figure 1) was carried out on the highly crystalline methanesulphonate (5).This revealed a cis configuration for the double bond. Applic- ation of Horeau's method 'to the determination of the absolute stereochemistry of the hydroxy group showed that it possessed OHfi-CHzOH HOCH2 f 1) 0 I H (9) the 'S' configuration. Thus structure (3) represents the overall stereochemistry of the lactone.Cephalosporolide C, C,,,H,,O,, M+ 216 (4)showed a broad hydroxy absorption at 3 400 cm-' and a lactone absorption at 1725 and 1250 cm-'. However, it lacked the i.r. and U.V. absorption of the ap-unsaturated ketone of cephalosporolide B. The 13C n.m.r. spectrum (Table 1) contained signals that were attributed to a methyl group, four methylene groups, three -CH*O-groups, and a lactone and a carbonyl group. 'H N.m.r. spin decoupling studies established several part structures from which the overall structure was deduced. Irradiation of the methyl group doublet (61.27) and the multiplet resonance at 6 5.13 resulted in changes in the spectrum consistent with the part structure (12). Irradiation at the multiplet at 6 4.25 removed a 844 +OH 0 OH 0I II I II CH;CH* CH,--C* CH; CH *CH=CH*C -(12) (13 1 A/0 OH OH 0 0 00 0 II I I II II II I CH2*C --C-CH2-C-C-CH,-C--C CH,* C H CH 11 I (141 HH 0 (15) 0' 6) Figure 1.Structure of cephalosporolide B 3-O-methanesulphonate (5) small coupling (3 Hz) from a double doublet at 6 2.93 (J 3 and 18 Hz) and a large coupling (J 12 Hz) from a further double doublet (J 12 and 18 Hz) at 2.35 and modified a multiplet at 6 3.44. Irradiation of the latter signal collapsed a two-proton signal at 6 2.75 to a doublet and affected the multiplet at 6 4.25. Further irradiation at 6 2.93 resulted in the collapse of the signal at 6 2.35 and 4.25 revealing a coupling of 10 Hz between the signals at 6 4.25 and 3.44.This led to the part structure (14). The magnitude (10 Hz) of the coupling between the protons of the vicinal glycol indicated a trans relationship in this system. The overall structure, 3,4-dihydroxy-6-oxodecan-9-olide(4) which followed from these partial structures was confirmed by X-ray analysis (see Figure 2) and by an inter-relationship with thiobiscephalosporolide A. The cephalosporolides B and C were inter-related with thiobiscephalosporolide A (2) in the following way. Oxidation of compound (2) with sodium metaperiodate in acetic acid gave the corresponding sulphoxide. Unlike thiobiscephalosporolide A, this formed only a monomethanesulphonate on treatment with methanesulphonyl chloride in pyridine, possibly because of the involvement of one hydroxy group in hydrogen bonding with the sulphoxide.Pyrolysis of the sulphoxide led to the isolation of the 3-O-methanesulphonate of 6-oxodec-4-en-9- olide (5)which was also prepared from cephalosporolide B by treatment with methanesulphonyl chloride. Treatment of cephalosporolide C (4) with methanesulphonyl chloride gave an unstable dimethanesulphonate (6) which on pyrolysis also afforded the 3-O-methanesulphonate of 6-oxodec-4-enolide (5). J. CHEM. SOC. PERKIN TRANS. I 1985 Table 1. I3C N.m.r. signals of the cephalosporolides B-F (determined in CDCl, at 25 MHz) G1p.p.m. r 7 Carbon (3) (4) (7) (8) (9) 1 168.6 160.1 172.8 175.6 175.4 2 43.3 44.1 39.7 41.4 42.0 3 64.0 69.6 69.7 77.1 76.9 4 138.5 75.1 38.3 83.1 83.6 5 132.5 46.8 21.5 37.3 36.7 6 207.7 200.0 34.8 114.9 115.3 7 38.5 42.8 76.1 34.0 35.8 8 32.3 37.8 19.0 31.1 32.2 9 71.3 72.3 74.8 76.5 10 18.9 25.0 20.7 22.6 Table 2.'H N.m.r. signals of the cephalosporolides B-F (determined in CDCl, at 220 MHz) 6lp.p.m. A I > Proton (3) (4) (7) (8) (9) 2 2.45 2.35 2.62 2.52 2.68 2.95 2.93 2.95 2.67 2.73 3 5.22 4.25 4.15 4.82 4.75 4 5.8 3.45 1.75 5.09 5.05 5 6.25 2.75 n.a.* 2.02 2.27 2.33 2.46 6 1.75 7 n.a.* n.a.* 4.75 1.99 2.05 8 2.05 2.05 1.35 1.33 1.67 2.00 2.05 9 5.05 5.13 4.10 4.15 10 1.25 1.27 1.10 1.23 * n.a. = Not assigned. Table 3. 'H N.m.r. coupling constants of the cephalosporolides B-F Protons 15 18 12 19 18H2.4-H.?B 3 12 6 1.5 0.5H2A-H 3 6 3 3.5 8 6H2B-H3 9 10 6 5H344 12H4-H5 H4-H5A 4 6 2 4 0 7H4-H5B Hs*-Hs, 14 15 9H6A-H7 3H6B-H7 H7-H8 6 H**-H, 7 7.5 4 5.0H8B-H9 6.5 6.5 7 6H9-H 10 All three samples had identical i.r.and n.m.r. spectra, m.p., mixed m.p., and rotations. There are two suprising aspects of the inter-relationship. The first is the generation of the same compound on elimination of the C-4 epimers and the second is the stability of the 3-O-methanesulphonate. Examination of the X-ray structures of thiobiscephalosporolide A and of cephalosporolide C reveals that the epimeric hydrogen atoms at C-5 can come sufficiently close to the sulphoxide in one case and the methanesulphonate in the other to permit a syn elimination and thus afford the cis-olefin.The X-ray structure J. CHEM. SOC. PERKIN TRANS. I 1985 n C(10) Figure 2. Structure of cephalosporolide C (4) of the methanesulphonate also suggests that the stability of the 3-methylsulphonoxy group may lie in its preference for a conformation in which the methanesulphonate is too far from the hydrogen at C-2 for thermal syn elimination to occur. Cephalosporolide D,CgH1403, M+ 158 (7)showed i.r. absorption at 3 420 (OH) and 1690 cm-'. Unlike the other cephalosporolides, the 3C n.m.r. spectrum possessed only eight signals which were assigned to a methyl group, four methylene groups, two CHO groups, and one CO-0 group.'H N.m.r. spin decoupling studies showed that the methyl group doublet 6 1.48(J6.5Hz) was coupled to a CHOCO signal at 6 4.75.The spectrum also contained two double doublets at 6 2.65 (J 5.5 and 12.5 Hz)and 6 2.97 (J 4.5 and 12.5 Hz) which were geminally coupled (J 12.5 Hz). They were also coupled to a CHOH resonance at 6 4.15. This led to the structure 3-hydroxyoctan-7-olide (7) for the metabolite. Application of Horeau's method7 to the determination of the absolute stereochemistry of the alcohol showed that it had the 'S' configuration. Two further isomeric C, ,H 404lactones, cephalosporolides E (8) and F (9)were isolated from another fermentation of C. aphidicola grown under sulphur limiting conditions. Unlike the previous lactones they showed a single carbonyl absorption at 1770-1 780 cm-' (y-lactone) and no hydroxy absorption.Their 13C n.m.r. spectra (see Table 1) contained ten signals including singlets at 6 114.8 (E)and 115.3 (F) which were assigned to an acetal carbon. In addition there were three -CH-0- signals, four methylenes, and a methyl group. Bearing in mind the lack of hydrogy absorption in the i.r. spectrum, the '3C n.m.r. spectra require the presence of two cyclic ethers and a y-lactone ring. Whilst the 'H n.m.r. spectra bore some similarities to the other cephalosporolides there were some significant differences. In the case of cephalosporolide E, irradiation at 6 4.07 rather than at a lower field signal led to collapse of the methyl group doublet S 1.1 (J 7 Hz) to a singlet and caused perturbations to signals at 6 1.36and 2.00indicating the presence of the system (12).Irradiation of the resonance at 6 4.82 collapsed a triplet at 6 5.09 (J 6 Hz) to a broad doublet, removed an 8 Hz coupling from a double doublet (J8 and 19 Hz)at 6 2.67 and a 1.5 Hz coupling from a second double doublet (J 1.5 and 19 Hz) at 6 2.52. Irradiation at 6 5.09 collapsed the signal at 6 4.82 to a broad doublet (J 8 Hz), removed a 6 Hz coupling from a double doublet (J6and 14 Hz) at 6 2.04,and sharpened a doublet (J 14 Hz) at 6 2.33. This data can be accommodated in part structure (M),leading to several plausible structures for the acetal. In view of the shortage of material, the final structure (8) but not the absolute con-figuration was elucidated by X-ray analysis, (see Figure 3).A v Figure 3. Structure of cephalosporolide E (8) (4) hb 0.AOH *OH ti HO H +O@O 'OH u--4 I (8) (9) Scheme. Formation of cephalosporolides E and F, (8)and (9) comparable set of 'H n.m.r. decoupling studies based on irradiation of the resonances at 6 1.23, 2.46,4.16,4.75, and 5.04 in cephalosporolide F suggest that it is the epimer (9). Cephalosporolides E and F could arise by hydrolysis of cephalosporolide C, relactionization and acetal formation (see. Scheme). However, attempts to mimic this in the laboratory were unsuccessful. Nevertheless, since these compounds were isolated only on one occasion after extensive chromatography, it is possible that they were artefacts of the isolation procedure.Experimental Isolation of the Cephalosporolides B-F.-A sample (50g) of the crude residues obtained from a commercial fermentation of Cephalosporium aphidicola after the crystallization of aphidi- Colin, was chromatographed on silica (Merck, 7734,deactivated with 15 w/v water) (1 kg). Elution with 70 ethyl acetate- light petroleum gave a fraction which was purified by further chromatography on silica and crystallization from ethyl acetate-light petroleum to afford cephalosporolide B (3) (200 mg) as needles, m.p. 119-122 "C, aD20 + 145" (c 5.4 in CHCI,) (Found: C, 60.8; H, 6.85. C10H14O4 requires C, 60.6; H, 7.12), vmax.(Nujol) 3 320, 1 730, 1 690, and 1 640 cm-'; A,,,.215 nm (E 5 080); m/z 198 (lx),180 (3,165 (l), 152 (3,138 (50), 125 (40), 1 11 (43), and 55 (100). The 'H and 13Cn.m.r. data are tabulated. Elution with 90 ethyl acetate-light petroleum gave a fraction which was again purified by further chromatography on silica to afford cephalosporolide D (7) (300 mg) as needles, m.p. 130-132 "C, aID2O -46.5" (c 2.23 in CHCl,) (Found: C, 60.8;H, 8.9. C8H140, requires C, 60.7; H, 8.9); vmax.3 420, 1690 cm-'; m/z 158 (0.279, 140 (l), 125 (0.8), 114 (13), and 42 (100).Elution with ethyl acetate gave a third fraction which was purified by further chromatography and crystallization to afford cephalosporolide C (4) (500 mg), m.p. 93-96 "C, ccID2'+75" (c 1.7 in CHCI,) (Found: C, 55.6; H, 7.43.ClOH16O5 requires C, 55.5; H, 7.46); v,,,. 3400, 1725 cm-'; m/z 216 (0.3), 198 (0.6), 170 (5), 154 (8), 139 (lo), 127 (95), 101 (52), 83 (90), and 55 (100). On one occasion the residues (10 g) from C. aphidicola grown under sulphur limiting conditions were chromatographed on silica. Elution with 60 ethyl acetate-light petroleum gave cephalosporolide E (8) (590 mg) which crystallized as prisms, m.p. 101 "C, aD3' +51.3" (c 0.42 in CHCl,) (Found: C, 60.6; H, 7.3. C10H1404 requires C, 60.6; H, 7.12), v,,,. 1 770 cm-'; mjz 198 (8), 183 (lo), 154 (48), 143 (52), 139 (43), 127 (60), 111 (53), and 56 (100). Elution with 2 methanokthyl acetate gave cephalosporo- lide F (9) (194 mg), m.p. 58-60 "C (Found: C, 60.6; H, 7.2. C1OHl4O4 requires C, 60.6; H, 7.12), v,,,.1 780 cm-'; m/z 198 (573, 183 (7), 154 (27), 143 (43), 127 (55), 11 1 (50),and 56 (100). Oxidation of Thiobiscephalosporolide A.-The bislactone (200 mg) in glacial acetic acid (10 ml) was treated with sodium metaperiodate (120 mg) in water (1 ml) at room temperature. After 90 min the solvents were evaporated and the product was chromatographed on silica to afford 4,4'-sulphinylbis(3- hydroxy-6-oxodecan-9-olide)(2) (100 mg), m.p. 155-158 "C -49" (c 0.24 in EtOH) (Found: C, 53.7; H, 6.4. C,,H,,O,S requires C, 53.8; H, 6.77); v,,,, 3 340, 1725, 1 708, and 1 050 cm-'; G(CHC1,) 1.25 (6 H, d, J 7 Hz), 3.57 (2 H, m, CHS), 4.68 (2 H, m, CHO), 5.07 (2 H, m, CHOCO). The mono- methanesulphonate, prepared with methanesulphonyl chloride in pyridine, had m.p.118-120 "C, RID2" -41" (c 0.2 in CHC1,) (Found: C, 48.4; H, 6.5. C21H32011S2 requires C, 48.1; H, 6.15);vmaX.3 400br, 1 740, 1 710, and 1 050 cm-'; 6 1.26 (6 H, m), 3.1 (3 H, s, MeSO,), 4.65 (1 H, m, CHO), 5.1 (2 H, m, CHOCO), and 5.55 (1 H, m, CHOS0,Me). Pyrolysis of the Monomethanesu1phonate.-The above methanesulphonate (900 mg) was heated at 130 "C for 20 min in uacuo. The residual black gum was chromatographed on silica in toluene-ethyl acetate (8:2) to afford the 3-methanesulphonate (5) of cephalosporolide B (50 mg), m.p. 137-138 "C, aID3' + 173" (c 0.25 in CHC1,) (Found: C, 47.6; H, 6.0. Cl,H1606S requires C, 47.8; H, 5.84), v,,,. 1 745, 1 690, 1 640, 1 355, and 1 175 cm-'; h,,,, 219 nm (E 5 OOO); 6 1.27 (3 H, d, J 6 Hz), 3.13 (3 H, s), 5.00 (1 H, m), 5.67, 5.80 and 6.63 (1 H each).The same (i.r., n.m.r., "ID, and mixed m.p.) methanesulphonate was obtained from cephalosporolide B with methanesulphonyl chloride in pyridine. Cephalosporolide C bismethanesulphonate (6). This was pre- pared with methanesulphonyl chloride in pyridine. It crystal- lized from ethyl acetate-light petroleum as needles, m.p. 124 "C, aID3O +38" (c 0.2 in CHCl,) (Found: C, 38.9; H, 5.4. J. CHEM. SOC. PERKIN TRANS. I 1985 C12H2,09S2 requires C, 38.7; H, 5.41); v,,,. 1735, 1715, and 1 700 cm-'; 6 1.3 (3 H, d, J6.5 Hz), 3.1 and 3.17 (each 3 H, s,OSO,Me),and 5.1(3 H,m,CHOR). Pyrolysis of the Bismethanesulphonate (6).--The bismethane-sulphonate (200 mg) was heated at 120 "C in vacuo for 5 min.The residue was chromatographed on silica in toluene-ethyl acetate to afford the 3-methanesulphonate (5) of cephalosporo-lide B, m.p. 139-140°C, +173", identical with the material described above (i.r., n.m.r., and mixed m.p.). Crystal Structure Determinations.-(a) Cephalosporolide B 3-0-methanesulphonate (5). C, HI 606s, M = 276.3, ortho- rhombic, a = 5.545(1), b = 11.272(1), c = 20.739(2) A, U = 1 296.3 A3, Z = 4, D,= 1.42 g cm-,, QOOO) = 584. Mono- chromated Mo-K, radiation, h = 0.71069 A, p = 2.7 cm-'. Space group P2'2,2, from systematic absences of h00 for h odd, OK0 for k odd, and 001 for 1odd. (b)Cephalosporolide C (4). C1 ,H 1605,M 2 16.24, monoclinic, u = 5.566(1), b = 7.759(2), c = 12.633(3) A, p = 92.84(2)", U = 544.9 A3, Z = 2, D,= 1.32 g ~m-~ QOOO) = 232.Mono- chromated Mo-K, radiation h = 0.71069 A, p = 1.1 cm-'. Space group P2 from systematic absences of OM) for k odd and successful refinement. (c) Cephalosporolide E (8). C,,H1404, A4 = 198.2, ortho- rhombic, a = 6.431, b = 9.967, c = 15.518 A, U = 994.7 A3, Z = 4, D,= 1.32 g cm-,, F(0o0)= 424. Monochromated Mo-K, radiation, h = 0.710 69 A, p = 1.1 cm-'. Space group P2'2,2, from systematic absences of hOO for h odd, OM) for k odd, and 001 for 1 odd. In each case data were measured on an Enraf-Nonius CAD4 diffractometer using a crystal of ca. 0.25 x 0.25 x 0.25 mm. Preliminary cell dimensions were found using the SEARCH and INDEX routines of the CAD4 and final values were calculated from the setting angles for 25 reflections with 8 ca. 15".Intensities for hkl reflections with 2 o(F2)were used in the structure refinement.The values of o(F2) were taken as 02(l)+ (O.O31)'*/Lp. The structures were solved by direct methods using the MULTAN program. Refinement of non- hydrogen atoms with anisotropic temperature factors was by full-matrix least-squares. Hydrogen atoms were placed at cal- culated positions (C-H 1.08 A) and held fixed with a common isotropic temperature factor of B = 5.0 A'. Refinement con- verged at R = 0.055, R' = 0.082 when the maximum shift/error was 0.08 (cephalosporolide B 3-O-methanesulphonate), R = 0.051, R' = 0.057 when the maximum shiftlerror was 0.01 (cephalosporolide C), R = 0.047, R' = 0.056 when the maxi- mum shift/error was 0.01 (cephalosporolide E).The weighting schemes were w = 1/02(F). The final difference maps were everywhere featureless. The structure solutions and refinement were done on a PDP 1 1/34 computer using the Enraf-Nonius Structure Determin- ation Package. Scattering factors were taken from the Inter- national Tables for X-Ray Crystallography, 1974, vol. 4. Final atomic co-ordinates are listed in Tables 4-6. Lists of temper-ature factors and hydrogen atom positions have been deposited J. CHEM. SOC. PERKIN TRANS. I 1985 Table4. Fractional atomic co-ordinates ( x 10") of cephalosporolide B 3-Table 6. Fractional atomic co-ordinates (x 10") of cephalosporolide E O-methanesulphonate (5) with e.s.d.s.in parentheses (8)with e.s.d.s in parentheses X Y Z X Y Z 1487.0(27) 4 758.6(13) 6 358.9(6) 4 382(5) 4 669( 3) 6 146(2) 1 547(10) 7 059(4) 7 980(2) 3 541(5) 3 723(3) 7 934(2) 2 841(13) 3 035(4) 9 09q2) 6 945(6) 3 459(4) 8 076(3) 981(7) 4 68q3) 8 762(2) 2 716(6) 2 608(3) 6 ooo(2)2 949(8) 4 071(3) 6 89q2) 5 334(8) 3 072(5) 7 775(3) -893(8) 4 971(5) 6 573(2) 4 944(10) 1901(5) 7 197(3) 1 869(10) 4 072(4) 5 782(2) 2 766(9) 2 099(4) 6 866(3) 2 124(12) 3 65q5) 8 659(3) 1855(7) 3 2W5) 7 434(3) 2 361(14) 3 363(5) 7 973(2) 1 089( 7) 4 247(5) 6 801(3) 2 745(11) 4 485(5) 7 564(2) 2 425(7) 4 030(4) 6 021(3) 5 osq10) 5 085(6) 7 742(3) 1 722(8) 4 482( 5) 5 142(3) 5 253(12) 6 059(6) 8 104(3) 3 722(9) 4 554(6) 4 643(3) 3 142(13) 6 721(5) 8 335(3) 5 398(7) 4 835(5) 5 321(3) 3 025( 14) 6 971(5) 9 035(3) 6 34q11) 6 205(6) 5 299(4) 779(12) 6 466(6) 9 371(3) 77 1 (12) 5 118(5) 9 W2) -1454(15) 4 627(7) 9 743(3) 3 016(17) 6 115(6) 6 307(4) as a Supplementary Publication (SUP No.56165,13 pp.).* Final structure factors are available on request from the editorial Table 5. Fractional atomic co-ordinates ( x lo") of cephalosporolide C office. (4) with e.s.d.s in parentheses X Y Z 7 7435) 3 301 1427(2) References 5 737(8) 8 494(6) 3 591(3) 1 W. Dalziel, B. Hesp, K. M. Stevenson, and J. A. J. Jarvis, J. Chem. Soc.,7 862(5) 6 153(5) 3 220(2) Perkin Trans. I, 1973, 2841. 9 879(5) 8 255(5) 441(2) 2 M. J. Ackland, J. R. Hanson, A. H. Ratcliffe, and I. H. Sadler, J. Chem. 6 801(5) 5 9W5) -394(2) SOC.,Chem. Commun., 1982, 165. 7 072(9) 7 761(7) 3 039(4) 3 R. P. Mabelis, A. H. Ratcliffe, M. J. Ackland, J. R. Hanson, and P. B. 8 11 3(9) 8 523(7) 2 075(4) Hitchcock, J. Chem. Soc., Chem. Commun., 1981, 1006. 8 551(8) 7 283(6) 1 175(3) 4 T. Ishida and K. Wada, J. Chem. SOC.,Chem. Commun., 1975,209;K. 6 249(8) 6 645(6) 594(3) Wada and T. Ishida, J. Chem. Soc., Chem. Commun., 1976, 340; J,4 713(7) 5 457(6) 1252(3) Chem. SOC.,Perkin Trans. I, 1979, 1154. 5 9W8) 3 937(6) 1775(3) 5 M. Nukina, T. Sassa, and M. Ikeda, Tetrahedron Lett., 1980, 301; 4 841(9) 3 186(7) 2 731(4) Agric. Biol. Chem. (Japan), 1980, 44, 2761. 6 538( 10) 3 332(9) 3 691(4) 6 L. M. Jackman and S. Sternhell, 'Applications of NMR Spectroscopy 6 864(10) 5 190(8) 4 097(3) in Organic Chemistry,' Pergamon Press, Oxford, 1969, p. 302. 8 599( 12) 5 291( 11) 5 01 l(5) 7 A. Horeau and A. Nouaille, Tetrahedron Lett., 1971, 1939. * For details of the Supplementary Publications Scheme see Instruc- tions for Authors (1985)in J. Chem. Soc., Perkin Trans. I, 1985, Issue 1. Received 10th August 1984; Paper 411413
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