A Novel Synthesis of the Yohimbane Skeleton-Course of the Synthesis of 15,16,17,18,19,20-Hexadehydroyohimbane by Use of Palladium Catalyzed Insertion of Carbon Monoxide

Abstract

In the course of our continuing synthetic experiments on benzoquinolizidine² and indoloquinolizidine alkaloids³, we have recently utilized palladium catalyzed amidation⁴ for the synthesis of the berbine alkaloids⁵. In this present paper we wish to report, what we believe is the first successful utilization of the palladium catalyzed amidation for the synthesis of the hexadehydroyohimbane skeleton.