Question

The product of which of the following reactions undergo hydrolysis by SN1 mechanism? 

• A. C,D ONLY
• B. A,B,C ONLY
• C. B,C ONLY
• D. A,D ONLY

Hint:

In SN1 reactions, the stability of the carbocation is crucial. Reactions that involve the formation of a stable carbocation, such as those involving resonance or hyperconjugation, are more likely to undergo the SN1 mechanism.

Answer 1

The Correct Option is C

The SN1 mechanism involves the formation of a carbocation intermediate. For a reaction to proceed via the SN1 mechanism, the leaving group must leave, forming a stable carbocation, which is then attacked by the nucleophile.

• Option A: The reaction of \( {C}_6{H}_5{Br} \) with water leads to the formation of phenol via an SN1 mechanism. This is an SN1 reaction since the phenyl carbocation can stabilize due to resonance, promoting the substitution mechanism.
• Option B: In the reaction \( {CH}_2=CH{C}_6{H}_5 + {HBr} \), the formation of a carbocation intermediate from the alkene is a typical SN1 mechanism. This is because the alkene can undergo a Markovnikov addition, where the formation of a carbocation intermediate is stable enough for the substitution to occur.
• Option C: The reaction of \( {C}_6{H}_5{Cl} + {SOCl}_2 \) typically proceeds through the formation of an intermediate carbocation, making it an SN1 reaction. Here, the chloride ion leaves to form a stable carbocation, which is then attacked by the nucleophile.
• Option D: The reaction of phenyl alcohol with a weak nucleophile (like acetic acid) does not form a carbocation and thus does not proceed via an SN1 mechanism.

Thus, the correct options are (B) and (C).