Which one of the following substituents at paraposition is most effective in stabilizing the phenoxide ion?
Which one of the following substituents at paraposition is most effective in stabilizing the phenoxide
ion?
$-\mathrm{CH}_{3}$
$-\mathrm{OCH}_{3}$
$-\mathrm{COCH}_{3}$
$-\mathrm{CH}_{2} \mathrm{OH}$
Solution
Electron withdrawing group stabilises the benzene ring due to delocalisation of charge.
$\mathrm{CH}_{3}$ and $-\mathrm{CH}_{2} \mathrm{OH}$ are electron donating group and hence decrease the stability of benzene ring $-\mathrm{OCH}_{3}$ is weaker electron withdrawing group than $-\mathrm{COCH}_{3}$. Hence $-\mathrm{COCH}_{3}$ group more stabilize the phenoxide ion at $p$ -position.
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