Free radical cyclizations in alkaloid synthesis: (+)-heliotridine and (+)-hastanecine
作者:Joong-Kwon Choi、David J. Hart
DOI:10.1016/s0040-4020(01)97176-5
日期:1985.1
hydride and AIBN affords mixtures of reduction and cyclization products. Cyclization products partition between indolizidinones and pyrrolizidinones depending on the terminal alkyne substituent. When the terminal substituent is a trimethylsilyl group, synthetically useful yields of pyrrolizidinones are obtained. Applications of this chemistry to the synthesis of (+)-heliotridine (2) and (+)-hastanecine (3)
用氢化三丁基锡和AIBN处理苯硫内酰胺5a-f可得到还原和环化产物的混合物。取决于末端炔烃取代基,环化产物在吲哚啶酮和吡咯烷酮之间分配。当末端取代基是三甲基甲硅烷基时,可获得吡咯烷二酮的合成有用的产率。描述了该化学方法通过关键中间体37和38在合成(+)-氯代吡啶(2)和(+)-芥子碱(3)中的应用。