Cyclodextrins as chiral stationary phases in capillary gas chromatography. Part III: Hexakis(3‐O‐acetyl‐2,6‐di‐O‐pentyl)‐α‐cyclodextrin

Abstract

Enantioselective gas chromatography a-Cyclodextrin Lactones Diols 0-Al kylgl ycerols Chiral pharmaceuticals SummaryThe properties of hexa kis(3-0-acetyl-2,6-di-O-pentyl)-a-cyclodextrin as a chiral stationary phase for capillary gas chromatography are described. For the first time the enantiomers of a series of different lactones are separated and their order of elution is assigned. Moreover, the enantiomers of trifluoroacetylated aldols and amino alcohols, the cyclic carbonates of 1,2-diols, 1 ,3-diols, 0-alkylated glycerols, and some chiral pharmaceuticalsarealso separated on the new chiral phase. The modified a-cyclodextrin is stable above 20OoC.

Influence of derivatization on the chiral selectivity of cyclodextrins: Alkylated/acylated cyclodextrins and γ‐/δ‐lactones as an example

“…Studies on the chiral selectivity of hexakis(2,6-di-O-pentyl-3-O-acetyl)-a-cyclodextrin showed high selectivity for the class of y-lactones [3,11]. However, &lactones, which differ by one more carbon atom in the ring, could not be separated on this cyclodextrin stationary phase.…”

“…They can be well separated into their enantiomers using several different types of 2,6di-O-alkylated-3 -0-acylated-cyclodextrins (e. g. , hexakis( 2,6-di-0-penty 1-3 -0-acetyl)-ar -cyclodextrin [3]). Enlarging the cavity inside the cyclodextrin molecule, i. e., working with the /3-or yhomologs, seems to have no influence on the chiral selectivity for the y-lactones.…”

Multidimensional gas chromatography/mass spectrometry: A powerful tool for the direct chiral evaluation of aroma compounds in plant tissues I. 5‐alkanolides in fruits

“…The development of sensitive capillary gas chromatographic methods for the enantio-differentiation of chiral flavour compounds occurring in natural matrices (Tressl and Engel, 1984;Tressl et al, 1985) has stimulated an interest in chiral evaluation of aroma substances exhibiting pronounced sensory properties, such as, e.g. elegant approach and excellent results have been obtained using alkylated cyclodextrin as the stationary phase (Konig et al, 1988a;Nowotny et al, 1989). However, the resolution of enantiomers by means of hexakis(3-U-acetyl-2,6-di-U-pentyl)-a-cyclodextrin (Lipodex B) has only been achieved for y-lactones (Bernreuther et al, 1989;Mosandl et al, 1989a;Nitz et al, 1989a, b).…”

Separation efficiency versus resolution: Chiral separation of gamma lactones by capillary GC on derivatized cyclodextrin

“…glass capillary, was leached and silylated with diphenyltetramethyldisilazane (DPTMDS, Fluka)/triphenyltrimethylcyclotrisiloxane (Petrarch Systems) 1 : 1 according to Blum [4]. It was statically coated with 2,6-di-0-pentyl-3-0-acetyl-a-cyclodextrin [ 5,6) and OV-170 1 -OH (1: 2) to form a film of 0.2 pm thickness. The column was equipped with a 30 cm uncoated fused silica inlet, attached by a press-fit connection.…”