Concise total synthesis of (±)-pileamartines A and B

Abstract

A concise total synthesis of (±)-pileamartines A and B, a pair of alkaloids sharing an unprecedented tetracyclic skeleton, was achieved in 9 and 8 linear steps, respectively. The key steps include an NHC-catalyzed tandem aza-benzoin/Michael reaction to rapidly establish the polyhydroindenopyrrole core, a diastereoselective reductive allylation of pyrrolidone, and an RCM to construct the piperidine ring.