Scalable Enantioselective Total Synthesis of (−)‐Goniomitine

Going, going, goniomitine: A scalable enantioselective synthetic strategy featuring an iridium‐catalyzed asymmetric hydrogenation of an exocyclic enone ester for the total synthesis of (−)‐goniomitine and formal syntheses of (+)‐1,2‐dehydroaspidospermidine, (+)‐aspidospermidine, and (+)‐vincadifformine is reported.

Abstract

A scalable enantioselective total synthesis of (−)‐goniomitine has been developed by using an iridium‐catalyzed asymmetric hydrogenation of an exocyclic enone ester to control the configuration of the molecule. The synthesis begins from commercially available starting materials, and proceeds through an integrated asymmetric ketone hydrogenation, Johnson–Claisen rearrangement, and one‐pot oxidation/deprotection/cyclization process. With this highly efficient and scalable strategy, (−)‐goniomitine was synthesized in eleven steps with 27 % overall yield, and formal enantioselective syntheses of (+)‐1,2‐dehydroaspidospermidine, (+)‐aspidospermidine, and (+)‐vincadifformine were also achieved.

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