One-pot conversion of activated alcohols into terminal alkynes using manganese dioxide in combination with the Bestmann–Ohira reagent

Abstract

The direct conversion of activated primary alcohols into terminal alkynes through a sequential one-pot, two-step process involving oxidation with manganese dioxide and then treatment with the Bestmann–Ohira reagent is described. This transformation proceeds efficiently (59–99% yield) under mild reaction conditions with a range of benzylic, heterocyclic and propargylic alcohols. A tandem variant is also described, which is successful only with highly activated substrates.