CHIRAL INTERACTIONS OF THE FLUOROETHER ANESTHETICS DESFLURANE, ISOFLURANE, ENFLURANE, AND ANALOGS WITH MODIFIED CYCLODEXTRINS STUDIED BY CAPILLARY GAS-CHROMATOGRAPHY AND NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY- A SIMPLE METHOD FOR COLUMN-SUITABILITY SCREENING

Eighteen chiral analogues of the chiral fluoroether anesthetics desflu rane, isoflurane, and enflurane are synthesized and studied by capilla ry GC on four cyclodextrin-derived stationary phases. Trends in separa bility and elution order of enantiomers are related to structure and a bsolute configuration. In particular,a very large separation factor is found for the commercial anesthetic desflurane using Lipodex(R) E sta tionary phase, suggesting that a preparative enantiomer separation is possible. One of the stationary phases, Cyclodex(R) G-TA, is found to be a chiral shift reagent for several of the fluoroethers. A rough cor respondence is found relating the enantiomeric separation factor of a fluoroether and the chemical shift differences between its H-1 and F-1 9 nuclei in the NMR spectrum. Based on this data, it is proposed that a simple NMR experiment can screen chiral stationary phases prior to a desired gas chromatographic enantiomer separation of a given chiral c ompound.