Hg(OTf)2-Catalyzed Instantaneous Hydration of β- and δ-Hydroxy Internal Alkynes with Complete Regioselectivity

The hydration of beta- and delta-hydroxy internal alkynes catalyzed by Hg(OTf)(2) took place instantaneously to give ketones with complete regioselectivity under mild conditions, whereas the hydration of internal alkyne without hydroxy moiety was very slow and gave a mixture of ketones. If the hydroxy group is located more than five carbons from the triple bond it has no significant effect upon the hydration reaction.