Stereoisomeric flavour compounds LXXX: alkyl-branched alkanals – stereodifferentiation, structure elucidation and structure – function relationship

The direct enantioseparation of 2-methylbutanal, 2-methylpentanal, 2-ethylhexanal, 3-methylpentanal and 4-methylhexanal was achieved using enantioselective gas chromatography and the chiral stationary phase heptakis-[2,3-di-O-acetyl-6-O-tert.butyldimethylsilyl]-β-cyclodextrin (DIAC-TBDMS-β-CD). Odour characteristics and threshold values of detection for compounds were evaluated by enantioselective gas chromatography/olfactometry. Enantiopure reference compounds with defined absolute configurations were synthesized starting from the corresponding alcohols or acids which were commercially available or prepared in the laboratory.