Concise Total Synthesis of (−)‐Calycanthine, (+)‐Chimonanthine, and (+)‐Folicanthine

Conjoined twins: An efficient and convergent strategy for the synthesis of the dimeric hexahydropyrroloindole alkaloids, (+)-chimonanthine, (+)-folicanthine, and (−)-calycanthine, is described. The simultaneous formation of the vicinal quaternary stereocenters by using a reductive dimerization reaction provides an access to the optically active key intermediate on a gram scale.