Stereochemical study on planar-chiral cyclic molecules using polysaccharide-based column chromatography.

The presence of planar chirality of a variety of medium-sized heterocycles, along with nine-membered cyclic ketone and its enol ester, was revealed by observation of isolable enantiomers by analytical high-performance liquid chromatography (HPLC) using a chiral stationary phase with a polysaccharide-based chiral selector. Several tens of milligrams of enantiomers of the planar-chiral molecules were successfully separated by preparative-scale HPLC, leading to the preparation of an enantioenriched sample. This in turn enabled detailed stereochemical studies, including measurement of half-lives of the optical activity and X-ray crystallography for elucidation of stereochemistry.