JEE Main Chemistry question

Ph–C≡C–CH₃ (Hg²⁺/H⁺)→ A, A is:

(A)Ph–CO–CH₂–CH₃ (propiophenone)Correct
(B)Ph–CH₂–CO–CH₃ (phenylacetone)
(C)Ph–CH=CH–OH (an enol, not tautomerized)
(D)Ph–CH(OH)–CH=CH₂

Answer: (A)

Solution

Mercuric-ion-catalyzed (Markovnikov) hydration of an aryl-substituted alkyne places the new C–OH (and, after tautomerization, the carbonyl) on the carbon attached to the aromatic ring, because the adjacent phenyl ring stabilizes the developing positive character at that carbon in the mercurinium-ion-opening transition

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Question ID VK-149826