Chemical Properties
Beta-Damascone is a colorless to pale yellow
liquid with a very powerful floral, complex fruity note, reminiscent of plum,
rose, and blackcurrant. ??-Damascone is found as a volatile constituent of many
natural materials, for example, in rose oils and extracts.
One synthetic route to the damascones starts with an appropriate cyclogeranic
acid derivative (halide, ester, etc.). This is reacted with an allyl magnesium halide
to give 2,6,6-trimethylcyclohexenyl diallyl carbinol, which on pyrolysis yields the
desired l-(2,6,6-trimethylcyclohexenyl)-3-buten-l-one. Damascone is obtained by
rearrangement of the double bond in the side chain.
The ??- and ??-damascones are used in perfume compositions, especially rose
perfumes, and in flavor compositions, to which they impart naturalness and body.
Occurrence
In Burley tobacco oil; in volatile fractions from leaves of Carphephorus corymbosus and C. paniculatus.
Reported found in bilberry, butter, milk, caviar, chicken fat, cooked beef and mutton, cured pork, pork and beef fat, roasted filberts
and peanuts, pecans, potato chips, soybean, coriander leaf and seed and kiwifruit.
Preparation
Various methods: recently from ionone izoxazoles, also from 7,8-dehydro-β-ionole.
Aroma threshold values
Detection: 8.6 to 41 ppb
Taste threshold values
Taste characteristics at 30 ppm: green, woody, minty with a herbal floral nuance.
