Enantiospecific Total Syntheses and Assignment of Absolute Configuration of Cannabinol‐Skeletal Carbazole Alkaloids Murrayamines‐O and ‐P

Abstract

First enantiospecific total syntheses of the cannabinol-skeletal carbazole alkaloids murrayamines-O and -P isolated from root barks of Murraya euchrestifoli, have been accomplished by highly diastereoselective, Lewis acid catalyzed coupling reactions of commercially available monoterpenes with carbazole derivative, which in addition to confirming the structure also established the absolute configuration of the natural products. Synthesis of both natural products and their enantiomers was achieved with high atom economy, in a protecting-group free manner and in six steps longest linear sequence from commercially available aniline derivative and verbenol.