Question

Which of the following reactions of glucose can be explained only by its cyclic structure?

(a) Glucose forms Penta acetate
(b) Glucose reacts with hydroxylamine to form an oxime.
(c) Pentaacetate of glucose does not react with hydroxylamine.
(d) Glucose is oxidised by nitric acid to gluconic acid.

Answer 1

(c) Pentaacetate of glucose does not react with hydroxylamine.

Due to the absence of free ‘OH’ group at C₁ cyclic structure of glucose Penta acetate cannot revert to open-chain aldehyde form and hence cannot form Penta acetate.