Chemical Transformation of Protoberberines. XVII. Biomimetic Introduction of an Oxy Functionality at the C-10 Position in the Benzo(c)phenanthridine Skeleton: Synthesis of 2,3,7,8,10-Pentaoxygenated Benzo(c)phenanthridine Alkaloids, Chelilutine and Sanguilutine.

Abstract

An efficient and biomimetic introduction of an oxy functionality at the C-10 position in the benzo[c]phenanthridine skeleton was developed by regioselective oxygenation with salcomine-oxygen. This biomimetic procedure was successfully applied to a synthesis of 2, 3, 7, 8, 10-pentaoxygenated benzo[c]phenanthridine alkaloids, chelilutine (8) and sanguilutine (18), from the corresponding 2, 3, 7, 8-tetraoxygenated benzo[c]phenanthridines.