Asymmetric Phase Transfer Reactions Catalyzed by Chiral Crown Ethers Derived from Monosaccharides

One of the practical applications of sugar-based crown ethers involves their use as chiral catalysts in enantioselective phase transfer reactions. Chiral crown ethers incorporating various monosaccharide units in the macrocyclic structure are reviewed which may be efficient enantioselective catalysts in certain asymmetric reactions, such as Michael addition, epoxidation of α,β-enones and Darzens condensation.