STEREOSELECTIVE EPOXIDATION OF ALLYLIC ALCOHOLS AND DEHYDROGENATIVE OXIDATION OF SECONDARY ALCOHOLS BY MEANS OF t-BUTYL HYDROPEROXIDE AND ALUMINIUM REAGENTS.

Treatment of a solution of geraniol and (t-BuO)//3Al in benzene with t-BuOOH at 5 degree C gives (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83% yield after acetylative workup. Eight allylic alcohols are converted to alpha , beta -epoxy alcohols in preparative yields. The epoxidation of secondary (E)-allylic alcohols shows opposite stereo-selectivities to t-BuOOH-VO(acac)//2 system. Asymmetric epoxidation with a chiral hydroxamic acid as a ligand gives unsatisfactory degrees of enantiomeric excess. The same system can also convert secondary alcohols into ketones in excellent yields, while primary ones react very slowly.