Alkynyl sulphones reactions

An alternative approach for alkynyl carboxylates involved reaction between [bis(acyloxy)iodo]benzenes and lithium acetylides [59]. Alkynyl iodonium salts afforded with sodium carboxylates in the presence of water 1-acyloxyketones heating in an excess of acetic acid gave similarly a-acetoxy ketones [60], Alkynyl tosylates and mesylates were obtained from the thermal decomposition of isolable alkynyl iodonium sulphonates. 

Reactions at a jSy-alkynyl function in an acetylenic sulphone (140) give products indicating the influence of the sulphonyl group, e.g. the formation of the vinyl sulphone (141), which gives j8-keto-sulphones through cleavage of the oxetan ring at different points on acid hydrolysis. 

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