Hydration, mercuric catalyzed mechanism

Reaction of acetone with D30+ yields hexadeuterioacetone. That is. all the hydrogens in acetone are exchanged for deuterium. Review the mechanism of mercuric ion-catalyzed alkyne hydration, and then propose a mechanism for this deuterium incorporation. 

Propose a mechanism to explain how the mercuric triflate-catalyzed hydration of 126 produces 127. 

The mechanism for the mercuric-ion-catalyzed hydration of an alkyne is shown next. The intermediate formed in the first step should remind you of the cychc hromonium ion formed as an intermediate in the addition of Br2 to an alkene (Section 6.9). 

Formulate a plausible mechanism for the hydration of ethyne in the presence of mercuric chloride. (Hint Review the hydration of alkenes catalyzed by mercuric ion. Section 12-7.)... 

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