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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3co104

Which statements about the Cannizzaro reaction of benzaldehyde with concentrated NaOH are correct? (One or more answers)

  1. AHydroxide adds to the carbonyl carbon in the first step.
  2. BA hydride ion is transferred from the tetrahedral anion to another aldehyde molecule.
  3. CThe molecule that is oxidised ends as the alcohol.
  4. DThe reaction needs at least one alpha-hydrogen on the aldehyde.

Answer: A, B

Hydroxide adds to C=O to form . This transfers hydride to a second aldehyde molecule. The oxidised molecule becomes the carboxylate and the reduced one becomes the alcohol. An alpha-hydrogen is not needed and its presence would lead to aldol reaction.
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