Search any question & find its solution
Question:
Answered & Verified by Expert
Write the reactions of D-glucose which can't be explained by its open chain structure. How can cyclic structure of glucose explain these reactions?
Solution:
2251 Upvotes
Verified Answer
(i) Glucose has aldehyde group in its structure but it does not give Schiff's test and does not give hydrogensulphite addition product with $\mathrm{NaHSO}_3$. These are reactions of carbonyl group but glucose does not give these reactions.
(ii) Glucose forms a six membered ring in which-OH at C-5 is involved in the ring formation. This explains the existence of glucose in two different crystalline form $\alpha$-form and $\beta$-form as shown below.
Due to cyclic structure -CHO group of glucose does not remain free to show the reactions of carbonyl group.
(ii) Glucose forms a six membered ring in which-OH at C-5 is involved in the ring formation. This explains the existence of glucose in two different crystalline form $\alpha$-form and $\beta$-form as shown below.
Due to cyclic structure -CHO group of glucose does not remain free to show the reactions of carbonyl group.
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.