Y-Damascenone

The conversion of y -ionone 18 into the structural isomer y damascenone 22 [86] exemplifies a transformation which can only be achieved with difficulty by other routes ... 

In this reaction, y ionone is converted into its oxime 19 which is oxidized to the isoxazole 20 by a special method (reaction with KJ and NaHC03 in THF/water). The compound 20 is converted into y damascenone by use of sodium in liquid ammonia in the presence of er/-butanol without isolation of the intermediate y amino ketone 21 yield 72% (based on y ionone). In this reaction, the heterocycle facilitates a 1,3-carbonyl migration within an a,y0-unsaturated carbonyl system. 

Figure G1.8.4 An FID chromatogram of concentrated extract of Niagara grape juice drawn to display the data on a linear retention index scale where the y axis is flame ionization response (upper trace). Below it is the charm chromatogram, where the / axis is dilution value. By simply comparing the index of a peak with the data listed in the Flavornet (see Internet Resource), it is possible to determine which odorants have similar retention indices. Notice how large the methyl anthranilate peak is, whereas there is no convincing peak for p-damascenone in the FID chromatogram, even though both compounds have the same potency in the charm chromatogram.

In a more recent study, Bailly et al. (2009) investigated the stability of key odorants during bottle aging in Sautemes wines. Except for 3SH, polyfunctional thiols were found unstable. However, most other key odorants (e.g., sotolon, phenylethanol, esters, y-lactones, p-damascenone, etc.) were still detected within 5-6 years. 

Kotseridis, Y., Baumes, R.L. Skouroumounis, G. (1999). Quantitative determination of free and hydrolytically liberated [J-damascenone in red grapes and wines using a stable isotope dilution assay. J. Chromatog., 849, 245-254. 

Kotseiidis, Y, Baumes, R., Skouroumounis, G. K. (1998). Synthesis of labelled pH4]-(3-damascenone, pH2]-2-methoxy-3-isobutylpyrazine, pH2]-ct-ionone, and pH3]-(3-ionone, for quantification in grapes, juices and wines. J. Chromatogr. A, 824, 71-78. 

Beeswax, white Beeswax, yellow Benzoic, acid Benzyl tiglate y-Bisabolene Brominated vegetable oil 3-Butylidenephthalide Butyloxepanone 3-Butylphthalide Calcium lactate Caramel Castor (Ricinus communis) oil Citronellyl isovalerate Citronellyloxy acetaldehyde p-Cresyl isovalerate p-Cresyl octanoate Crotonic acid p-Cyclocitral p-Damascenone 9-Decenal trans-4-Decenal Diacetyl tartaric acid esters of mono- and diglycerides Diethyl malate Difurfuryl disulfide Dihydroeugenol Dihydro-a-ionone Dihydrojasmone Diisobutyl ketone Diisopropyl disulfide 3,4-Dimethylcyclopentane-1,2-dione Dimethyl dicarbonate 2,5 Dimethyl-3-furanthiol p-a-Dimethylstyrene Diphenyl oxide Ethyl acetate... 

For example, the main odour-active components of Bourbon whisky are aldehydes, the most important of which are 3-methylbutanal, 2-methylbutanal, 2-methylpropanal and (2 , 4 )-deca-2,4-dienal. Important components are also ethyl esters, such as butanoate, 2-methylpropanoate, (S)-2-methylbutanoate, 3-methylbutanoate, hexanoate and octanoate, and lactones, especially (3S,4S)-whisky lactone, 8-nonalactone and y-decalactone, some phenols (vaniUm and eugenol) and (E)-P-damascenone, which is a degradation product of carotenoids. 

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