About the stereoselectivity control in reactions of chiral ortho-sulfinyl benzyl carbanions with aldehydes

Reactions of aliphatic and aromatic aldehydes with the benzyllithium derived from 2-p-tolylsulfinyl ethylbenzene yield mixtures of mainly two compounds, and , epimers at hydroxylic carbon, easily separated by chromatography and desulfinylated into enantiomerically pure 1-alkyl (or aryl)-2-phenyl-1-propanols. The observed stereoselectivity at C(1) and C(2) is analyzed to the light of the steric and electronic effects of the substituents.