Influence of the Nature and Substitution of Chiral 2,3-Epoxy Alcohol Derivatives on the Enantiomeric Elution Order on Chiralcel OD Column

A number of 2,3-epoxy alcohol derivatives (1–16), obtained either as racemates or through the Sharpless asymmetric epoxidation reaction, were studied on a Chiralcel OD column. Nearly all compounds exhibit good enantioselective resolution on this chiral support. The order of elution of enantiomers is reversed between nerol and geraniol compounds. For 2,3-epoxy alcohols bearing a remote alkoxy (or silyloxy) group, the order of the enantiomeric elution alternates with the number n (n = 1–3) of methylenic groups present between the epoxide ring and the terminal OR (R = p − BrBn or OSitBuPh2) functionality. In the case of trans 2,3-epoxy alcohols for the same number n, the order of elution is reversed when changing the terminal group −OSi to −OR. The latter group greatly improves the separation of the two enantiomers.