The regiospecific formation of olefins by the thermal elimination of sulphenic acid from /I-trimethylsilyl sulphoxides followed by protodesilylation is reported and the effect of the trimethylsilyl group on the thermal elimination is discussed. ... Elimination from a sulphoxide plays an important role in synthetic organic chemistry because it provides a means for the facile introduction of a double b0nd.l If there are two possible directions for such an elimination, it is necessary to ...