Diastereodivergent additions of aluminum and magnesium reagents to [(S)S]-3,6-dimethoxy-2-(p-tolylsulfinyl)-benzaldehyde

Enantiomerically pure [(S)S]-3,6-dimethoxy-2-(p-tolylsulfinyl)-benzaldehyde, prepared in two steps from commercially available 2,5-dimethoxybenzyl alcohol, reacted with organomagnesium and organoaluminum derivatives in a highly diastereodivergent way giving rise respectively to the (S) or (R) alkyl aryl or diaryl carbinols in excellent chemical and optical yields. Enantiopure (S) and (R)-2,5-dimethoxyphenyl methyl carbinols were obtained through a two-steps sequence comprising nucleophilic addition of MeMgBr or AlMe3 and desulfinylation with n-BuLi.