Synthesis and analysis of thio-, thiono-, and dithio-derivatives of whiskey lactone.
Cis- and trans-3-methyl-4-octanolide (1, whiskey lactones) were converted into their thio- (2), thiono- (3), and dithio- (4) derivatives by reaction with phosphorus pentasulfide. The reaction products were characterized by GC-mass spectrometry, (1)H NMR spectroscopy, and GC-olfactometry. Two-dimensional NOESY spectra showed that sulfur is incorporated into the ring with reversal of the absolute configuration at C-4, whereas substitution of the keto-oxygen atom by sulfur occurs with retention of ring configuration. The cis- and trans-pairs of 2, 3, and 4 were separated into enantiomers by GC on heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin and heptakis(2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin as chiral stationary phases. GC-olfactometry revealed a sweet coconut-like odor for the cis-thio- and pleasant mushroom-like flavors for the cis-thiono- and trans-dithio-derivatives of whiskey lactone.
Schmarr
H G
HG
Lehrstuhl für Allgemeine Lebensmitteltechnologie, Technische Universität München, Am Forum 2, D-85350 Freising-Weihenstephan, Germany. hg.schmarr@wzw.tum.de
Eisenreich
W
W
Engel
K H
KH
D000434:Alcoholic Beverages / Q000032:analysis*; D002849:Chromatography, Gas; D007783:Lactones / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry; D009812:Odorants / Q000032:analysis; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000032:analysis / Q000138:chemical synthesis* / Q000737:chemistry
D007783:Lactones; D013438:Sulfhydryl Compounds