Diversity of Products in the Gold‐Catalyzed Cyclization of 1‐Epoxy‐1‐alkynylcyclopropanes by Using 1‐Oxyallyl Cations

Abstract

A highly stereoselective AuCl3-catalyzed hydrative cyclization of 1-epoxy-1-alkynylcyclopropanes was observed for cis-epoxides. Since this cyclization produced 1-oxyallyl cations efficiently, we accomplished a two-step [4+2] annulation of epoxyalkynes with dienes and enones, to provide complex oxacyclic compounds with excellent diastereoselectivity (see scheme).