Nucleophilic reactions in ethylenic derivatives. Part IX. “Direct substitution” and “elimination–addition” mechanisms in the reaction of arylsulphonylchloroethylenes with alkoxide ions

Abstract

cis-p-Tolylsulphonylhalogenoethylenes react with alkoxide ions by “direct substitution” and by “elimination–addition” mechanisms. A method based on the determination of the equilibrium concentration of the intermediate p-tolylsulphonylacetylene was worked out which enabled the contributions of the two mechanisms to the overall reaction to be determined.

The method was applied to a few typical cases and it was found that the participation of the “elimination–addition” process to the overall reaction is important in the cases studied. Some preliminary results on the base-catalysed addition of alcohols to p-tolylsulphonylacetylenes are also reported.