Treatment of hydroxythiol with α, α-diethoxyacetophenone at room temperature yielded a mixture of epimeric S, O-acetals and (1: 4, 92% yield), which were efficiently separated by flash chromatography. The OTBS derivatives and were treated with several Grignard reagents to afford carbinols and respectively (85–99% yield,> 95% dr). After successive hydrolysis and reduction of 10 and 13 it is possible to obtain either enantiomer of diols in ...