On the Stereochemical Divergence in the Conjugate Addition of Lithium Dimethylcuprate/Trimethylsilyl Chloride to γ-Alkoxy and γ-Ureido α,β-Unsaturated Esters

Abstract

A comparative study was made of the reaction of chiral non-racemic γ-alkoxy and γ-ureido-α,β-unsaturated esters with lithium dimethylcuprate in the presence of trimethylsilyl chloride. The possible origins of the anti- and syn-additions respectively are discussed and rationalized.