Hydroxyl-Directed Conjugate Additions of Carbon Nucleophiles to Cyclopentadienones

Abstract

[Structure: see text] The conjugate additions of different carbon nucleophiles to cyclopentadienone substrates (1 and 2) with one free hydroxyl functional group were investigated to determine the role of the hydroxyl group in controlling regiochemistry. During this reaction an unexpected intramolecular displacement of OTBS by the enolate intermediate occurs, to afford cyclopropane derivatives.