Warming a phenol with a carboxylic acid gives an ester only with difficulty, whereas an alcohol reacts readily. This is because

  • A. phenols contain no hydroxyl group
  • B. the phenolic oxygen donates its lone pair into the ring, making it a poorer nucleophile
  • C. phenols are stronger bases than alcohols
  • D. esters cannot contain a benzene ring

Explanation

Delocalisation of the oxygen lone pair into the aromatic system, the very effect that makes phenol acidic, leaves that oxygen less available to attack the carbonyl carbon of an acid. Phenyl esters are therefore prepared using more reactive acyl chlorides or anhydrides instead. The same delocalisation also shortens and strengthens the carbon to oxygen bond in phenol.

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