A General Strategy for the Construction of Calyciphylline A‐Type Alkaloids: Divergent Total Syntheses of (−)‐Daphenylline and (−)‐Himalensine A

Abstract

AbstractAn efficient general strategy for the synthesis of the Daphniphyllum alkaloids via the rapid construction of a common core intermediate has been established, based on which a divergent total synthesis of (−)‐daphenylline and (−)‐himalensine A has been accomplished in 16 and 19 steps, respectively. The present work features an enantioselective Mg(ClO4)2‐catalyzed intramolecular amidocyclization to construct the aza‐bridged core structure; a Cu‐catalyzed intramolecular cyclopropanation and subsequent phosphine‐catalyzed Cope‐type rearrangement to furnish the himalensine A scaffold; and a one‐pot Diels–Alder/aromatization method to assemble the aromatic skeleton of daphenylline.