Evidence is presented that the regiospecific and often stereospecific pseudo-Diels–Alder reactions of 1,3-dienes with N-acyl immonium salts, derived from 5-ethoxy-2-pyrrolidinone, are stepwise reactions. 6,7-Dehydroindolizidinones, unsaturated lactam esters, and new indene and furan derivatives are described. A synthesis of dl-gephyrotoxin 223AB (indolizidine 223AB) from trans-1,3-heptadiene was achieved
有证据表明,1,3-二烯与衍生自
5-乙氧基-2-吡咯烷酮的 N-酰基亚
铵盐的区域特异性和通常立体特异性的假狄尔斯-阿尔德反应是逐步反应。描述了 6,7-脱氢 indolizidinones、不饱和内酰胺酯和新的
茚和
呋喃衍
生物。实现了从反式-1,3-庚二烯合成 dl-gephyrotoxin 223AB(
吲哚里西啶 223AB)。