Regioselective synthesis of hydroxy sulphides via trifluoroacetoxysulphenylation of derivatives of allylic alcohols

Abstract

Reaction of manganese(III) acetate with diphenyl disulphide in dichloromethane–trifluoroacetic acid in the presence of allylic esters gives trifluoroacetoxy sulphides, which on hydrolysis readily afford vicinal hydroxy sulphides. With acetate esters, neighbouring group participation by the acetate functionality controls the reaction course. Thus regiospecific addition to allyl acetate affords after hydrolysis only 3-phenylthiopropane-1,2-diol. In contrast, with trifluoroacetate esters the inductive effects of the trifluoroacetate functionality lead to a different regiocontrol. Thus addition of diphenyl disulphide to allyl trifluoroacetate gives after hydrolysis only 2-phenylthiopropane-1,3-diol. The regio- and stereochemistry of addition to a variety of other allylic (and homoallylic) esters is described and the extension of this type of regiocontrol is discussed.