Divergent Asymmetric Total Syntheses of (-)-Alloaristoteline and (+)-Aristoteline via Directed Indolization Strategies.

A divergent asymmetric synthetic route to (-)-alloaristoteline and (+)-aristoteline is described. The key doubly bridged tricyclic enol triflate common intermediate prepared via enantioselective deprotonation and stepwise annulation was successfully bifurcated to complete the first completely synthetic construction of the titled natural alkaloids upon strategic implementation of the late-state directed indolization methods.