Oxidation of a D-hexose with nitric acid forms an optically active aldaric acid.A Wohl degradation of the same D-hexose followed by oxidation with nitric acid forms an optically active aldaric acid.What are the three possible D-hexoses that fit this data?
A)D-allose,D-altrose and D-glucose
B)D-glucose,D- mannose and D-talose
C)D-glucose,D-idose and D-altrose
D)D-galactose,D-talose and D-mannose

Question

Quizplus · Accepted Answer

The key to this question lies in understanding the chemical reactions and the structural implications for the hexoses. The oxidation of a D-hexose with nitric acid to form an optically active aldaric acid implies that the original hexose must have had a unique configuration at its carbon atoms, allowing for the formation of a specific aldaric acid. The Wohl degradation, which shortens the carbon chain by one and then followed by oxidation with nitric acid leading again to an optically active aldaric acid, suggests that the original hexose had a configuration that, even after losing a carbon atom, still resulted in a molecule that could be oxidized to an optically active aldaric acid. D-glucose, D-mannose, and D-talose fit these criteria because of their specific arrangements of hydroxyl groups, which allow for the formation of optically active aldaric acids through both processes described.

Oxidation of a D-Hexose with Nitric Acid Forms an Optically