ABSTRACT
In 1848 Louis Pasteur used a hand lens and a pair of tweezers to separate the sodium ammonium salts of p-tartaric acid into their component enantiomers (D-and L-tartaric acid), thereby accomplishing the first enantioselective resolution [1]. Pasteur also accomplished the first chemical resolution of a racemic compound when he neutralized a solution of L-cinchonin with racemic tartaric acid [2]. With this experiment, he demonstrated that the transformation of enantiomers into diastereomers converted molecules with the same physicochemical properties (enantiomers) into compounds with different physicochemical properties (diastereomers). Thus, while the solubilities of Dand L-tartaric acids were identical, the L-tartrate-L-cinchonin salt was crystallized before the D-tartrate-L-cinchonin salt.
