Synthesis and enantiomeric purity determination of chiral 3-benzylglycidol, a key synthon for HIV protease inhibitors.

The detailed synthesis of (2R,3R)-3-benzylglycidol by the Sharpless asymmetric epoxidation route is described. The enantiomeric purity determination of this compound is complicated by the presence of small quantities of the diastereometric (2R,3S)-3-benzylglycidol from the asymmetric epoxidation of the cis-allylic alcohol, and the unreacted allylic alcohols that are not removed in the product isolation steps. We have developed a direct chiral HPLC method that can resolve all these components for the precise determination of enantiomeric excesses of chiral 3-benzylglycidols.