Substitution of Hydroxyl Groups with Alkynyl Moieties Using Alkynylboron Dihalides:  An Efficient Approach to Secondary Alkylacetylene Derivatives

The reaction of alkynylboron dihalides with benzylic, allylic, and propargylic alcohols provides an efficient route to internal acetylenes. Isomerization of the product alkynes does not occur under the reaction conditions.