Question

How open chain structure of d-glucose is converted into cyclic structure?

Answer 1

In its fleeting open-chain form, theglucose molecule has an open (as opposed to cyclic) and unbranched backbone of six carbon atoms, C-1 through C-6; where C-1 is part of an aldehyde group H(C=O)-, and each of the other five carbons bears one hydroxyl group -OH.