Synthesis of Vinca Alkaloids and Related Compounds. Part LXIX. Synthesis of 15-Substituted Eburnane Derivatives

Starting from 15α-chlorovincamine (1), 15β-hydroxy-14-epivincamine (2a) and its 14-O-alkyl derivatives (2b, 2c) have been prepared via 14,15β-epoxyvincamine (3). The latter compound was transformed into (+)-15-oxodihydroeburnamine (6). The structures of 2-3 were established via detailed nmr investigations