Dmso - mediated reactions synthesis and rearrangement reactions of oxiranes

Abstract

Some intriguing aspects of the reactions between dimethylsulphoxide (DMSO), bromine and alcohols on the one hand, and oxirane rearrangements on the other, have been studied. Dimethylsulphoxide has been shown to react with molecular bromine at low temperatures and in dichloromethane as solvent to give dimethylsulphide~ dibromide (DMS-Br2). At low temperatures, the mixture of DMSO and br-orn i ne selectively oxidises secondary alcohols to ketones, while at high v temperatures, primary and secondary alcohols are transformed to methylne acetals. The dimethyl sulphidedibromide (DMs-Brr) salt also transforms alcohols to methylene acetals, and reacts with dimethylsulphoxide to give trimethylsulphoniurn bromide