Question

Enumerate the reactions of D -glucose which cannot be explained by its open chain structures.

Answer 1

Following reactions cannot be explained by the open chain structure of glucose.
(1) Glucose has aldehyde group but it does not react with 2,4 dinitro phenyl hydrazine, sodium bisulphite and Schiff's base.
(2) There is no condensation reaction between glucose penta-acetate and hydroxylamine. This indicates that free aldehyde group is absent.