Cycloaliphatic unsaturated ketones as odour- and taste-modifying agents

DETAILED DESCRIPTION We claim: 1.
Process for the preparation of compounds of the formula ##SPC14## containing an isolated double bond in position 1 or two conjugated double bonds in position 1 and 3, the double bonds being represented by the dotted lines, and wherein the substituents R.
sup.
1 and R.
sup.
2 may be the same or different and each represents a hydrogen atom or a lower alkyl radical containing from 1 to 6 carbon atoms, which comprises treating a diol having the formula ##SPC15## comprising a saturated or mono-unsaturated six membered ring, the double bond being indicated by the dotted line and wherein R.
sup.
1 and R.
sup.
2 have the meaning indicated above, with phosphoric acid, sulphuric acid, trifluoroacetic acid, p-toluene sulphonic acid, acid diatomaceous earths or an acidic cation exchange resin.
2.
Process according to claim 1 in which the diol is treated with diluted sulphuric acid.
3.
Process according to claim 1 wherein the reaction between the diol and the acid is carried out in the presence of a salt of copper nickel or mercury.
4.
Process according to claim 1 where the reaction is carried out at a temperature of between about 40.
degree.
and 90.
degree.
C.




Description:
SUMMARY OF THE INVENTION The invention relates to a new process for the preparation of unsaturated cycloaliphatic ketones having the formula ##SPC1## Containing an isolated double bond in position 1 or two conjugated double bonds in position 1 and 3 of the ring, the double bonds being represented by the dotted lines, and wherein the substituents R.
sup.
1 and R.
sup.
2 may be the same or different and each represents a hydrogen atom or a lower alkyl radical containing from 1 to 6 carbon atoms, which process comprises treating a diol of formula ##SPC2## Comprising a saturated or mono-unsaturated six membered ring, the double bond being indicated by the dotted line, with an acidic dehydrating agent.
The invention relates further to a compound of formula ##SPC3## and to its use as flavouring and perfuming ingredient, as well as to certain of the intermediates formed during the above process