Total Synthesis of the Marine Sponge Alkaloid Motuporamine C Using a Ramberg-Backlund Ring Contraction Strategy

摘要

A new total synthesis of the marine alkaloid motuporamine C, a macrocyclic polyamine alkaloid from the marine sponge Xestospongia exigua, has been accomplished. Key steps of this synthesis include application of Ramberg-Backlund rearrange- ment for achieving the 15-membered aza-macrocyclic alkene and Rh(II)-catalyzed deoxygenation of epoxide for the conversion of E- to Z-configuration of the double bond within the cyclic structure.