Asymmetric Oxidation of Beta-hydroxysulfides - the Role of the Hydroxy Group

In the asymmetric oxidation of prochiral \u3b2-hydroxysulfides to the corresponding sulfoxides, by using a recently developed modified Sharpless reagent, it has been observed that the presence of the hydroxy group in the molecule of the substrate is not playing a significant role in determining the extent of the enantioselection, at variance with the asymmetric epoxidation of allylic alcohols where formation of alkoxytitanium complexes is believed to be a crucial process, thus indicating some important difference in the oxidation mechanisms