PtCl₂‐Catalyzed Hydrative Cyclization of Trialkyne Functionalities to Form Bicyclic Spiro Ketones

Abstract

Triple rounds: A regioselective hydrative cyclization of triynes has been developed to give bicyclic β-hydroxy spiro ketones, which undergo subsequent dehydration to give the β,γ-unsaturated ketones (see scheme). Model reactions suggest that this platinum catalysis includes two selective hydrations, an alkyne insertion, and an aldol condensation.