Alkyne formation in the reaction of α-bromo ketones with arylsulfonylhydrazines

Abstract

Alkynes can be produced by treating some α-bromo ketones with arylsulfonylhydrazines. The reaction is acid-catalysed and mesitylsulfonylhydrazine was the most efficient hydrazine reagent examined. The mechanism of the reaction has not been elucidated although it is shown not to proceed via an α-bromo mesitylsulfonylhydrazone.