Synthesis of Optically Active #alpha#-Methyl #beta#-Hydroperoxy Esters by Diastereoselctive Singlet Oxygen Ene Reaction and Horseradish Peroxidase Catalyzed Kinetic Resolution

摘要

Optically acitve diastereomeric #beta#-hydroperoxy esters 4 have been prepared by singlet oxygen ene reaction of #beta#,#gamma#-unsaturated esters 3 and subsequent horseradish peroxidase (HRP) catalyzed kinetic resolutionof the ene product. The highest enantiomeric excess (up to 95%)has been obtained for the isopropyl ester threo-4c, which estabolishes that the size of the remote ester functionality exercises appreciable control in the enantioselectivity of the enzymatic kinetic resoltion.