Toward an Enantioselective Total Synthesis of Sarain A:Construction of an Advanced Intermediate and Rearrangement of the Sarain A Core under Mild Conditions

摘要

A high-yielding N-sulfonyliminium ion-enoxysilane cyclization and a ring-closing metathesis are key steps in the enantioselective synthesis of late-stage intermediates en route to sarain A.Also revealed is an unprecedented rearrangement of the tetracyclic sarain A core under mildly acidic conditions.