Total Synthesis of Indole Alkaloid Alsmaphorazine D

A concise total synthesis of rac‐alsmaphorazine D has been described for the first time. The efficient synthetic strategy features four key transformations: 1) a catalytic intramolecular oxidative cyclization for the δ‐lactamindole backbone; 2) an oxidative cyclic aminal formation for the hexahydropyrrolo[2,3‐b]pyrrole framework; 3) a transannular radical cyclization for the construction of the diazabicyclo[3.3.1]nonane structure; and 4) a one‐pot desilylation/double epimerization reaction that affirms the relative stereochemistry. The total synthesis of (±)‐alsmaphorazine D was achieved in a concise and efficient fashion. The key features of the strategy are based on a catalytic intramolecular oxidative cyclization, an oxidative cyclic aminal formation, a transannular radical cyclization, and a one‐pot desilylation/double epimerization reaction. CAN=cerium(IV) ammonium nitrate.