Answer to Question #102551 in Chemistry for Megha

Question

What are anomers? Explain the existence of anomers in sugars taking D-glucose as
an illustrative case.

Answer 1

Anomers are epimers that are characterized by different configurations at the acetal or hemiacetal carbon. Anomers are epimeric glycosides or saccharides that are different by the configuration of the first carbon (aldoses) or second carbon (ketoses).

D-glucose has two possible anomers: α-D-Glucopyranose and β-D-glucopyranose. Alpha and beta configurations of D-glucose depend on the configuration of the anomeric carbon C1. As a result, if the hydroxyl group on this carbon and the -CH2OH group on C5 are on opposite sides of the cyclic D-glucose ring, D-glucose is an α-anomer, while if they are located on the same side, D-glucose is in the β-anomer configuration.