The Enantiomeric Differentiation Ability of Chiral Crown Ethers Based on Carbohydrates

The enantiomeric differentiation ability of chiral sugar-based crown ethers can be utilized for the determination of the enantiomeric composition of chiral amino compounds and for the separation of racemic amino compounds. Chiral crown ethers incorporating various carbohydrate units in the macrocyclic structure showing enantiomeric recognition towards chiral primary amines, amino acids and amino acid esters are reviewed here. The chiral recognition of organic ammonium salts by crown ethers may be tested with various methods. In this review, practical applications are also summarized, where the enantiomers of racemic amino compounds and their derivatives are separated by carbohydrate-based crown ethers immobilized on a stationary phase.