Cyclization of the open chain structure of $$D$$-$$(+)$$- glucose has created a new stereocenter at $${C_1}$$ which explains the existance of two cyclic forms of $$D$$-$$(+)$$- glucose, namely $$\alpha - $$ and $$\beta - $$. These two cyclic forms are diasteromers, such diasteromers which differ only in the configuration of chiral carbon developed on hemiacetal formation (it is $${C_1}$$ in glucose and $${C_2}$$ in fructose) are called anomers and the hemiacetal carbon ($${C_1}$$ or $${C_2}$$) is called the anomeric carbon.