Erythro and Threo Nomenclature
source : oc hempal.org
Erythro and Threo Nomenclature-
This nomenclature is based on four carbon aldose sugars ; erythrose & threose.
Compounds having two different chiral or assymetric carbon atoms are named by using prefix- erythro or threo. When two same groups are on the same side of chiral carbon atom in fischer Projection formula then it is ‘ erythrose ‘. When two identical groups are on the opposite side of chiral carbon atom in Fischer Projection formula then it is ‘threose’