Asymmetric epoxidation of allylic alcohols

摘要

Asymmetric epoxidation of allylic alcohols using carboxylic acid treated phenethyl hydroperoxide oxidate and titanium tartrate catalyst gave optically active glycidols following an enantioselection rule opposite to that observed from the Sharpless epoxidation (U.S. Pat. No. 4, 471,130). Overall yield and enantiomeric excess of the glycidol made are dependent on the amount of carboxylic acid present in the oxidate feed. This novel finding provides a direct epoxidation route to (R)-glycidol using the less expensive natural L-(+)-dialkyl tartrate ligand.