Asymmetric epoxidation of enol ethers and esters using iminium salt catalysts synthesis of α-Hydroxy-Carbonyls

Iminium salt organocatalysts can provide high selectivity and high efficiency in catalytic asymmetric epoxidation. Enantiomerically-enriched epoxides are useful intermediates that have found many applications in asymmetric synthesis, and development of efficient catalysts for asymmetric epoxidation has received considerable attention. In this manuscript, we describe the preparation, and use of highly selective iminium salt organocatalysts for asymmetric epoxidation. The new catalysts have been tested in the catalytic asymmetric oxidation of enols, and provide up to 98% ee. Also we tried to synthesize tatarinoid B 74 which used for the treatment of central nervous system diseases in traditional Chinese medicine