Asymmetric synthesis of β-hydroxyesters by aldol type condensation of enantiomerically pure t-butyl p-tolyl sulfinyl acetate: unexpected substituent effect on the absolute configuration of the product

Aldol type condensation of enantiomerically pure t-butyl p-tolyl sulfinyl acetate was shown to give the opposite configuration at the hydroxylic center in the case of an α,β-unsaturated aldehyde, a result which is in sharp contrast with literature results. The absolute configurations of the aldol products were determined by X-ray crystallography.