MolSynapsequestion bank
MolSynapse / Question bank / Aldehydes, Ketones and Carboxylic Acids / Aldol, Cannizzaro, Perkin, Claisen and related condensations
JEE Advanced levelSingle correct optionDifficulty 3 of 3co097

Benzaldehyde is heated with propanoic anhydride and sodium propanoate, and the mixture is then acidified. The main product is

  1. A3-phenylprop-2-enoic acid
  2. B2-methyl-3-phenylprop-2-enoic acid
  3. C2-methyl-3-phenylpropanoic acid
  4. D3-phenylbut-2-enoic acid

Answer: B

The enolate is formed from propanoic anhydride at next to C=O, which carries a methyl group. It adds to benzaldehyde, and elimination gives . This is 2-methyl-3-phenylprop-2-enoic acid, with the methyl on the alpha carbon.
Practice Aldehydes, Ketones and Carboxylic Acids More on Aldol, Cannizzaro, Perkin, Claisen and related condensations
Previous questionNext question

More questions on Aldol, Cannizzaro, Perkin, Claisen and related condensations