Total Synthesis of Indole Alkaloid AlsmaphorazineD

A concise total synthesis of rac-alsmaphorazineD has been described for the first time. The efficient synthetic strategy features four key transformations: 1)a catalytic intramolecular oxidative cyclization for the [delta]-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.