The use of cyclofructans as novel chiral selectors for gas chromatography

Abstract

Cyclofructans cannot be used as chiral stationary phases for GLC in their native states. This is due to their high melting points and their inability to be solubilized in other liquid stationary phases. However, when cyclofructans are derivatized (via the 3-, 4-, or 6-hydroxyl groups) they can then be dissolved in an achiral matrix and the mixture is suitable as a GLC chiral stationary phase. In this study, per-O-methylated cycloinulohexaose (PM-CF6), per-O-methylated cycloinuloheptose (PM-CF7) and 4,6-di-O-pentyl cycloinulohexaose (DP-CF6) were tested as new chiral selectors for GLC. Enantiomeric separations of several different compounds were observed when using the derivatized cyclofructans as chiral selectors. The enantiomers separated include esters, β-lactams, alcohols, and amino acid derivatives. Differences in the enantiomeric separations obtained by using PM-CF6, PM-CF7 and DP-CF6 as the chiral selector were observed. These differences gave some insight as to the mechanism of enantioselectivity for permethylated cyclofructans as GLC chiral selectors.