SummaryHeptakis(2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-P-cyclodextrin proves to be a versatile chiral stationary phase for the direct differentiation of aroma-relevant enantiomers.

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Abstract, tert-Butyldimethylsilylated cyclodextrin derivatives dissolved in polysiloxanes were shown to be versatile chiral stationary phases for the differentiation of important chiral food and flavor ingredients and chiral acids of biochemical and pharmaceutical interest.

The gas chromatographic separation of the 1‐p‐menthene‐8‐thiol enantiomers has been achieved using heptakis(2,3‐di‐O‐methyl‐6‐O‐TBDMS)‐β‐cyclodextrin as the chiral stationary phase in enantioselective gas chromatography. The sensory evaluation of the pure enantiomers has been realized by enantioselective gas chromatography‐olfactometry. (R)‐1‐p‐menthene‐8‐thiol was found to be of formative influence on the natural odour of grapefuit whilst the odour of the (S)‐enantiomer was weak and non‐specific.

Racemic mixtures of synthetic cis‐ or trans‐4‐methyl‐5‐decanolide were separated by enantioselective high performance liquid chromatography with Chiraspher‐RT to yield all four stereoisomers as enantiopure compounds of distinct odour activities. In order to elucidate stereochemical features the isolated stereoisomers were reduced to their corresponding 4‐methyl‐1,5‐decandiols by reductive ester cleavage with lithium aluminium hydride. Absolute configurations were derived from proton nuclear magnetic resonance studies of diastereomeric di‐(R)‐2′‐methoxy‐2′‐trifluoromethylphenylacetic acid esters of these 1,5‐diols. Using enantioselective multidimensional capillary gas chromatography (column combination SE 52/heptakis‐(2,3‐di‐O‐methyl‐6‐O‐tert butyldimethylsilyl)‐β‐cyclodextrin), the direct enantioselective analysis of all four lactone stereoisomers was achieved. The application of this method to the scent of living, white flowering orchids (Aerangis confusa) proves cis‐(4S)‐methyl‐(5S)‐decanolide as the unique and genuine stereoisomer of Aerangis lactone.