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JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Biomolecules

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The correct structure of product ' P ' in the following reaction is
  1. (A)(see structure)
  2. (B)(see structure)
    ✓ Correct
  3. (C)(see structure)
  4. (D)(see structure)

Answer: (B)

Solution

Excess acetic anhydride with a mild base acetylates the free nucleophilic sites of the dipeptide, namely an exposed amino terminus and the hydroxyl of the serine side chain, turning each into its acetyl derivative. The backbone amide linkages and the asparagine side-chain amide are unreactive under these conditions. The product is therefore the structure carrying acetyl groups on both the terminal nitrogen and the serine oxygen, with the amide nitrogens left untouched.

JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Single correct option

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