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NEETChemistryAldehydes and Ketones

Consider the following reagents: (i) Ammonia (ii) Sodium bisulfite (iii) Hydrazine (iv) Hydrogen cyanide (v) Semicarbazide How many of the above reagents react with benzaldehyde via a nucleophilic addition-elimination mechanism?

Options

  1. A2
  2. B4
  3. C5
  4. D3

Correct answer

D. 3

Step-by-step solution

Benzaldehyde reacts with ammonia derivatives ( NH ₂- Z ) via a nucleophilic addition-elimination mechanism, resulting in the formation of a > C = N - Z bond and the elimination of a water molecule. Among the given reagents: (i) Ammonia ( NH ₃ ) forms an imine (addition-elimination). (ii) Sodium bisulfite ( NaHSO ₃ ) forms a bisulfite addition product (pure addition). (iii) Hydrazine ( NH ₂ NH ₂ ) forms a hydrazone (addition-elimination). (iv) Hydrogen cyanide ( HCN ) forms a cyanohydrin (pure addition). (v) Semicar

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