SYNTHESIS OF VINCAMINE AND RELATED INDOLE ALKALOIDS

摘要

A process is taught for the synthesis of vincamine and related indole alkaloids, according to which, through only two steps and through a novel synthesis intermediate, namely the glycidic ester, having the formula IMAGE (III) wherein R'' represents -COOCH3 or -COOCH2CH3, 1-ethyl-1,2,3,4,5,6,7,12b-octahydroindole[2,3-a]quinolizine-1-carboxal dehyde is reacted with a haloester in the presence of a base and the glycidic ester is converted to vincamine or apovincamine or like esters by reaction with a Lewis acid or a mineral acid, the reaction products being subsequently separated by chromatography.