Name a compound having two similar asymmetric carbon atoms and give its structure. What type of isomerism does it exhibit? Draw Fischer projection formulas of these isomers and comment on their optical activity. How are they related to each other?

Explanation

Tartaric acid has two similar asymmetric carbon atoms (HOOC - CHOH - CHOH - COOH). The compound exhibits optical isomerism. Fisher projection formulas of its isomers are as follows:

The relations among the isomers are as follows: I and II are enantiomers, I and III are diastereoisomers and II and III are diastereoisomers.