Two aldopentoses, X and Y , give the same osazone derivative. X is oxidised to an optically active aldaric acid by dilute nitric acid. Ruff degradation of Y gives a tetrose which is similarly oxidised to an optically active aldaric acid. Assign the structures of X and Y from the following list. (i) (ii) (iii) (iv)

Step-by-step solution

Based on the given Fischer projections, the structures are identified as follows: (i) D-Ribose (ii) D-Lyxose (iii) D-Arabinose (iv) D-Xylose Two aldopentoses X and Y give the same osazone derivative, which means they are C-2 epimers. The possible epimeric pairs from the given structures are (i) and (iii), or (ii) and (iv). Compound X is oxidised by dilute nitric acid to an optically active aldaric acid. Let's check the aldaric acids formed by the given sugars: - Oxidation of (i) D-Ribose gives ribaric acid, which h