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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3bm183

Which statements are correct?

AKiliani-Fischer synthesis starting from D-arabinose gives a pair of C-2 epimeric aldohexoses, D-glucose and D-mannose.
BRuff degradation of D-glucose gives an aldopentose, D-arabinose.
CD-glucose and D-mannose give the same aldopentose on Ruff degradation.
DKiliani-Fischer synthesis from D-arabinose gives D-glucose and D-galactose.

Answer: A, B, C

Kiliani-Fischer adds one carbon at C-1; the new C-2 is formed with both configurations, giving C-2 epimers (glucose and mannose from arabinose, not galactose, which is a C-4 epimer). Ruff degradation removes C-1 and the epimeric centre C-2 is lost, so glucose and mannose both give D-arabinose.

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