STEREOISOMERIC FLAVOR COMPOUNDS .76. DIRECT ENANTIOSEPARATION, STRUCTURE ELUCIDATION AND STRUCTURE-FUNCTION RELATIONSHIP OF 4-TERT-BUTYL-ALPHA-METHYLDIHYDROCINNAMALDEHYDE

Using enantioselective gas chromatography and (2,3-di-O-acetyl-6-O-ter t-butyldimethylsilyl)-beta -cyclodextrin (DIAC-TBDMS-beta-CD) as the c hiral stationary phase, the direct enantioseparation of 4-tert-butyl-a lpha-methyldihydrocinnamaldehyde was achieved. The threshold values an d odour characteristics of the enantiomers were investigated by enanti oselective gas chromatography/ olfactometry. In order to elucidate ste reochemical features, the carbonyl-function was oxidized to the corres ponding acid and diastereomeric amides were generated with (S)-2-amino -2-phenyl-ethanol [L(+)-alpha-phenylglycinol] as the enantiopure reage nt. After separation and isolation by highperformance liquid chromatog raphy, absolute configurations were deduced from X-ray structure eluci dation of a pure stereoisomer. Amide cleavage, reduction and selective oxidation yielded the enantiomers of 4-tert-butyl-alpha-methyldihydro cinnamaldehyde.