I. All carbon inverse-electron-demand Diels-Alder reactions: Exploration of the chemistry of an electron-deficient diene. II. Synthesis of some 6,15-disubstituted 2,11-dithia[3.3]metacyclophanes.

摘要

Dienes which bear electron withdrawing groups at the 1- and 3-positions are formal electronic complements of dienes such as Danishefsky's diene. Surprisingly, the inverse-electron-demand Diels-Alder (IEDDA) chemistry of these types of dienes has received little attention in the literature to date. The synthesis of (2E)-3-(1′-oxo-2′-cyclohexen-2 ′-yl)-1-phenyl-2-propen-1-one (102), a novel electron deficient diene substituted in the 1- and 3-positions with electron withdrawing groups, is discussed.;The use of enamines as dienophiles led to the formation of dihydronaphthalenones. A domino IEDDA-elimination-dehydrogenation reaction is postulated to account for the formation of these products.;The chemistry of two additional dienes, 7-benzoyl-6-ethoxy- (133) and 7-benzoyl-6-hydroxy-3,4,4a,5-tetrahydro-1( 2H)-naphthalenone (167), derived from the IEDDA adduct of diene 102 with 131, was also examined.;As part of a cooperative effort within our group to study the solution state conformational preferences of substituted 2,11-dithia[3.3]metacyclophanes, 6,15-dibromo- (198) and 6,15-diiodo-2,11-dithia[3.3]metacyclophane (199), as well as 2,11-dithia[3.3]metacyclophane (192) have been synthesized. The 6,15-difluoro- (196) and 6,15-dichloro-2,11-dithia[3.3]metacyclophanes (197) were also targeted for synthesis, however the Na2 S/Al2O3 coupling technique used was unsuccessful for these compounds. (Abstract shortened by UMI.).