This explains the absence of —CHO
group and also existence of glucose in two forms as shown below These two cyclic forms exist in equilibrium with open chain structure The two cyclic hemiacetal forms of glucose differ only in the
configuration of the hydroxyl group at C1, called anomeric carbon
Cyclic
Structure
of Glucose
Rationalised 2023-24
286
Chemistry
(the aldehyde carbon before cyclisation) Such isomers, i