Question

In which of the following is the removal of $C{l}^{-}$ most difficult?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

By removal of $C{l}^{-}$ , the positive charge get formed on $s{p}^2$ hybridized carbon of aromatic ring in option (d) which makes it very unstable. Hence, the relpacement of $C{l}^{-}$ is most difficult in (d).
While -ve charge formed on allyl and benzyl system is always stablizied by resonance and in option (1) the +ve charge is stabilized by hyperconjugation of $C{H}_3$ group.