Generation of cations from alkoxides: Allylation of propargyl alcohols

A study was conducted to show that cations intermediate could be generated from the corresponding coupling of a lithium alkoxides with an alkyne in the presence of boron trichloride. Contrary to the reaction of alkoxides with alkenylboron dichloride reaction of alkoxides with alkynes in the presence of boron trichloride gave E-alkenyl chlorides as major products.