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