Gold-Catalyzed Tandem Meyer-Schuster / Ring Expansion Reaction Leading to alpha-Hydroxy-alpha-Vinyl Cyclopentanes

Abstract

Gold-catalyzed tandem Meyer-Schuster rearrangement / ring expansion of 2-butyne-1,4-diol derivatives has been developed, leading to α-hydroxy-α-vinyl cyclopentanes. Recently, gold catalysts have enabled the Meyer–Schuster rearrangement from propargyl alcohols under mild conditions leading to α,β-unsaturated ketones. A group selective Meyer-Schuster rearrangement from alkyne-1,4-diols led an enone attached to cyclobutanol moiety, which then underwent an ring expansion via 1,2-alkyl shift. The generality of this tandem Meyer-Schuster rearrangement has been demonstrated. Furthermore, enantioselective ring expansion has been studied employing various monophosphine ligands.