A Ring Fragmentation Approach to Medium-Sized Cyclic 2-Alkynones

Abstract

Bicyclic γ-silyloxy-β-hydroxy-α-diazoketones, in which the Cβ-Cγ bond is the ring fusion bond, productively fragment when treated with tin(IV) chloride to provide medium-sized cyclic 2-alkynones. This method provides good to excellent yields of 10-, 11-, and 12-membered alkynone products.