Reinvestigation of the Cleavage of Canadine, A Protoberberine Bearing a Methylenedioxy Function, with Sodium in Liquid Ammonia

Abstract

Two products, 3‐hydroxy‐9,10‐dimethoxyprotoberberine and 3,9‐dihydroxy‐10‐methoxyprotoberberine in addition to those reported, 2‐hydroxy‐9,10‐dimethoxyprotoberberine and 2,9‐dihydroxy‐10‐methoxyprotoberberine, were identified from cleavage of canadine with sodium in liquid ammonia. This reaction indicates regioselectivity rather than the reported regiospecificity by cleavage mainly at a site para to the N‐methine carbon.