Which reagent is most suitable for the conversion of ${\text{CH}}_3\text{C}\equiv \text{CH}$ to ${\text{CH}}_3{\text{COCH}}_3$?

Solution

1. The hydration of terminal alkynes is catalyzed by ${\text{Hg}}^{2+}$ ions.
2. The reaction proceeds via the formation of a vinyl alcohol (enol) intermediate.
3. The enol undergoes tautomerization to form the more stable ketone, $\text{propan-2-one}$.
4. Hence the answer is (A).