Enantioselective Total Synthesis of (+)‐Flavisiamine F via Late‐Stage Visible‐Light‐Induced Photochemical Cyclization

Abstract

AbstractThe structural features Kopsia alkaloids, in particular multiple all‐carbon quaternary stereocenters in a caged and strained polycyclic skeleton, poses particular challenges for enantioselective total synthesis. Herein, we reported the first total synthesis of (+)‐flavisiamine F. The synthetic approach involved a room‐temperature Overman rearrangement for introducing the chiral amine at C21, a TMS‐promoted ketal Claisen rearrangement for constructing the all‐carbon quaternary stereocenter at C20, and a late‐stage visible‐light‐induced photochemical cyclization for establishing the all‐carbon quaternary stereocenter at C7.