Highly selective acetate aldol additions using mesityl-substituted chiral auxiliaries

Abstract

(Chemical Equation Presented) Highly diastereoselective acetate aldol additions using chlorotitanium enolates of mesityl-substituted N-acetyloxazolidinethione and N-acetylthiazolidinethione auxiliaries are reported. These additions proceed in high yields and diastereoselectivities (93:7 to 98:2) for aliphatic, aromatic, and α,β-unsaturated aldehydes. Double diastereoselective acetate aldol additions are also reported and are found to proceed in high yields and diastereoselectivities (90:10 to 97:3). © 2007 American Chemical Society.