2,3-di-O-methoxymethyl-6-O-tert-butyldimethylsilyl-gamma-cyclodextrin: a new class of cyclodextrin derivatives for gas chromatographic separation of enantiomers.

Octakis(2,3-di-O-methoxymethyl-6-O-tert-butyldimethylsilyl)-gamma-cyclodextrin (2,3-MOM-6-TBDMS-gamma-CD) was employed as stationary phase for capillary gas chromatographic separation of enantiomers. Selective introduction of the acetal function at positions 2 and 3 of the glucose units was achieved by reaction of 6-O-TBDMS-gamma-cyclodextrin with methoxymethyl chloride. 2,3-MOM-6-TBDMS-gamma-CD was shown to be a chiral stationary phase suitable for enantiodifferentiation of a broad spectrum of chiral volatiles from various chemical classes. A total of 125 pairs of enantiomers could be separated. Structural influences of the analytes on the enantioseparation were demonstrated. High alpha values up to 1.8 were observed for the hydroxyketone acetoin and some methyl branched ketones. Pronounced enantioseparations were also determined for cyclic pentenolone and furanone derivatives.