Question

Which one of the following substituents at para-position is most effective in stabilizing the phenoxide  ion?

Options

• −CH₃

• −OCH₃

• −COCH₃

• −CH₂OH

Answer 1

−COCH₃

Explanation:

Because of charge delocalisation, the electron-withdrawing group stabilises the benzene ring.

−CH₃ and −CH₂OH are electron-donating groups that reduce benzene ring stability. −OCH₃ is a weaker electron withdrawing group than −COCH₃.

As a result, the −COCH₃ group helps to stabilise the phenoxide ion at the para-position.