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Sulfonyl‐stabilized phosphonium ylids

1972; Royal Netherlands Chemical Society; Volume: 91; Issue: 1 Linguagem: Inglês

10.1002/recl.19720910106

1878-7096

A. M. VAN LEUSEN, B. A. Reith, A. J. W. Iedema, J. Strating,

Cyclopropane Reaction Mechanisms

Abstract Two general methods are given for the synthesis of mono‐sulfonyl‐substituted methylenephosphoranes, magnified image ( 1 ). (i) Methylenetriphenylphosphorane can be substituted by using sulfonyl fluorides to give 1. A similar reaction with sulfonyl chlorides, however, fails mostly, (ii) The synthesis of sulfonylmethyltriphenylphosphonium bromides ( 5 ) from bromomethyl sulfones and triphenylphosphine, due to Speziale and Ratts , was improved. The bromides 5 were readily transformed to 1 by base. As an extension of (i), the reaction of benzylidenetriphenylphosphoranes with sulfonyl halides has been studied. Contrary to previous reports it was found that the product from ethoxycarbonylmethylenetriphenylphosphorane and tosyl chloride is α‐ethoxycarbonyl‐ p ‐tolylthiomethylenetriphenylphosphorane, instead of the corresponding tosyl compound. Method (i), however, does not apply to ethoxycarbonylmethylenetriphenylphosphorane ( 16 ).