Glucose having ( i ) configuration about C1 is the α-glucose and having ( ii ) configuration about C1 is β-glucose .
The carbon C1 is known as anomeric carbon and these compounds are called anomers . Both the forms are optically active . ex-D-glucosehas specific rotation + 111.5 ° and β-D-glucose has specific rotation + 19.5 °.
Mutarotation
When either of the two forms of glucose is dissolved in water , there is a spontaneous change in specific rotation till the equilibrium value of + 52.5 °. This is known as mutarotation .
Properties of glucose
Glucose has one aldehyde group , one primary hydroxyl ( -CH2OH ) and four secondary hydroxyl ( -CHOH ) groups and gives the following reactions :
These reactions confirm the presence of a carbonyl group in glucose .