Himbacine Derivatives and Synthetic Analogues

A series of derivatives was prepared for pharmacological testing from himbacine and dihydrohimbacine, the latter compound obtained by von Braun degradation of dihydrohimbacine. The Mannich reaction with acetylenic acetates was used for the preparation of tertiary amines for testing. It was found that much improved yields were obtained by addition of catalytic amounts of copper(I) chloride and copper bronze to the reaction mixture.