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D-Glucose reacts with hydroxylamine to form an oxime and adds to form a cyanohydrin, but it completeBiomolecules Chemistry Question

Question

D-Glucose reacts with hydroxylamine to form an oxime and adds $HCN$ to form a cyanohydrin, but it completely fails to form the bisulphite addition product with $NaHSO_3$. What is the most accurate structural reasoning for this anomaly?

Answer: B

💡 Solution & Explanation

Open-chain glucose fails to react with $NaHSO_3$ or give a positive Schiff's test because it quickly cyclizes via an intramolecular nucleophilic addition into a stable 6-membered pyranose hemiacetal, heavily restricting the availability of the free aldehyde group required for weak nucleophiles.

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