Regioselective Synthesis of Chirally Enriched Tetrahydrocarbazolones and Tetrahydrocarbazoles.

A new one-step, reagent-directed regioselective synthesis of chirally enriched tetrahydrocarbazolones and tetrahydrocarbazoles from a common type of substrate has been developed. The salient features of this method include inherited stereodiversity, a broad substrate scope, a quick reaction time, and a benign catalyst. The method is applicable to the synthesis of a bioactive cryptosanguinolentine precursor.