ALKALOIDS OF STEPHANIA GLABRA . A DIRECT CHEMICAL CORRELATION OF ABSOLUTE CONFIGURATION OF SOME BENZYLTETRAHYDROISOQUINOLINE PROAPORPHINE AND APORPHINE ALKALOIDS . A NEW PROTOBERBERINE ALKALOID

Separation of the alkaloid bases of Stephania glabra yielded the proaporphines (+)-stepharine and (+)-pronuciferine, as well as the protoberberines (–)-tetrahydropalmatine, (–)-corydalmine, and (–)-stepholidine. Evidence is presented to support the structures assigned to the new alkaloids stepharine and stepholidine. The cleavage of proaporphines to benzyltetrahydroisoquinolines by sodium in ammonia is reported. The use of this cleavage reaction, considered together with the conversion'of proaporphines into aporphines, makes possible a chemical correlation of the absolute configuration of several alkaloids of the benzyltetrahydroisoquinoline, proaporphine, and aporphine groups. © 1968, American Chemical Society. All rights reserved.