Preparation of compounds of the 4-oxodamascone series, and novel scents from this class of compounds

摘要

Process for the preparation of the compounds of the formulae Ia and Ib ##STR1## wherein A. 2,4,4-trimethylcyclohex-2-en-1-one oxime of the formula IIb ##STR2## is treated with a strong aqueous acid at from 30. degree. to 80 C., preferably 40 to 70 C.,P PB. the resulting ketone of the formula IIIb ##STR3## is oxidized in a conventional manner, and C. if desired, the resulting compound Ib is isomerized in a conventional manner.PPCompounds of the formula A ##STR4## where R is one of the following radicals: --CH(OH)--CH. sub.2 --CHCH.sub.2 (IIIb), --CH(OH)--CH.sub.3 (IIIc), --CH.sub.2 OH (IIId), --CH(OH)--CHCH.sub.2 (IIIe), --CH(OCOCH.sub.3)--CH.sub.3 (IIIf), --CH.sub.2 --OCOCH.sub.3 (IIIg), --CO--CH.sub.2 --CHCH.sub. 2 (Ib), --CO--CH.sub.3 (Ic) and --CO--CHCH.sub.2 (Ie).P PThe compounds IIIb to IIIg, Ib, Ic and Ie are useful scents and aromas, and furthermore may become important intermediates for novel carotenoids. They can be prepared in a relatively simple manner from compounds which are very readily available.