CHIRAL RECOGNITION OF RACEMIC SUGARS BY POLAR AND NONPOLAR CYCLODEXTRIN-DERIVATIVE GAS-CHROMATOGRAPHY

Di-O-pentyl-derivatized cyclodextrins and (S)-hydroxypropyl-per-O-methyl-derivatized cyclodextrins were used as chiral stationary phases in capillary gas chromatography. Di-O-pentyl-derivatized cyclodextrins were rather apolar, whereas the O-hydroxypropyl per-O-methyl derivatives were relatively hydrophilic and could be dissolved in water. High enantioselectivity towards thirteen trifluoroacetylated sugars was observed with both sets of chiral stationary phases. Most of the sugars studied had their enantiomeric elution-order reversed on the different stationary phases. 2,6-Di-O-pentyl-3-O-trifluoracetyl-derivatized cyclodextrins, used as a g.l.c. stationary phase, showed behavior intermediate between the other two cyclodextrin derivatives. The chromatographic separation-factors with the dipentyltrifluoroacetyl derivatives were higher than the corresponding values on the two other sets of chiral stationary phases. All columns were stable over a wide range of operating temperature. © 1990.