A tellurium transposition route to allylic alcohols: overcoming some limitations of the Sharpless-Katsuki asymmetric epoxidation

Good yields of enantiomeric allylic alcohols can be obtained in high enantiomeric excess (ee) by combining the Sharpless-Katsuli asymmetric epoxidation process (SAE) with tellurium chemistry. The advantages of the tellurium process are as follows: (1) the 50% yield limitation on the allylic alcohol in the Sharpless linetic resolution (SKR) can be overcome; (2) allylic tertiary alcohols which are unsatisfactory substrates in the SKR can be obtained in high optical purity; (3) optically active secondary allylic alcohols with tertiary allyl substituents (e.g. tert-butyl) at C-1 can be obtained in high ee; (4) optically active sterically congested cis secondary alcohols can be obtained in high ee; and (5) the nuisance of the slow SAE of some vinyl carbinols can be avoided