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JEE Main · 2022 · 28 Jul 2022 · Shift 2 · Biomolecules

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The formulas of A and B for the following reaction sequence are
  1. (A)A = C₇H₁₄O₈, B = C₆H₁₄✓ Correct
  2. (B)A = C₇H₁₃O₇, B = C₇H₁₄O
  3. (C)A = C₇H₁₂O₈, B = C₆H₁₄
  4. (D)A = C₇H₁₄O₈, B = C₆H₁₄O₆

Answer: (A)

Solution

Glucose (C₆H₁₂O₆) reacts with HCN to form a cyanohydrin, which upon hydrolysis gives a hydroxy acid. This is then reduced with HI/P to give heptanoic acid (C₇H₁₄O₂). Oxidation with Br₂ water converts the aldehyde group to carboxylic acid, giving gluconic acid (A = C₇H₁₄O₈). Heating with HI reduces all hydroxyl and carboxyl groups to give n-hexane (B = C₆H₁₄). Therefore A = C₇H₁₄O₈ and B = C₆H₁₄.

JEE Main · 2022 · 28 Jul 2022 · Shift 2 · Single correct option

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