Enantioselective formal synthesis of ent-rhynchophylline and ent-isorhynchophylline

摘要

Starting from (S)-tryptophanol, a formal synthesis of ent-rhynchophylline and ent-isorhynchophylline, involving stereoselective cyclocondensation, spirocyclization, and alkylation reactions, and the final adjustment of the oxidation level at the oxindole and piperidine moieties, is reported.