Question

How would you separate (+)-or (-) - tartaric acid from meso-tartaric acid? How would you separate (+)-or (-) - tartaric acid?

Answer 1

A common way of separation of enantiomers uses the conversion into diastereomers, that are not mirror images of each other. The following example demonstrates this principle. The two enantiomers 1-phenylethylamine (S-(-), R-(+)) are separated using (L)-(+)-tartaric acid (also known as the (R,R)-form) as resolving agent.

The two salts formed possess different cation ions are therefore not enantiomers of each other anymore. The (S)-(1)-phenylethyl ammonium-(R,R)-tartrate salt crystallizes faster than the (R)-(1)-phenylethyl ammonium-(R,R)-tartrate salt.