The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 1990
Filed:
Jan. 31, 1990
Cyril Mahaim, Echichens, CH;
Firmenich S.A., Geneva, CH;
Abstract
The polyunsaturated compounds of formula ##STR1## having two conjugated double bonds in the endo- and exo- positions of the pentagonal cycle indicated by the dotted lines, and wherein symbols R.sup.1 and R.sup.2, when taken separately, represent respectively a. a linear or brached C.sub.1 to C.sub.4 alkyl radical and b. an hydrogen atom or a methyl radical, or, when taken together with the carbon atoms to which they are bonded form a polymethylenic cycle such as indicated by the dotted line, containing from 5 to 12 carbon atoms, and symbol R.sup.3 stands for an hydrogen atom or a methyl radical, n being an integer equal to 0 or 1, which are useful intermediate products for the preparation of odoriferous macrocyclic ketones, are prepared according to a process comprising a vapor phase cyclization of an enone of formula ##STR2## wherein the dotted line and the symbols n, R.sup.1, R.sup.2 and R.sup.3 are defined as above, effected by means of a thermal treatment of said enone in the presence of a cyclization catalyst consisting of an aluminum, silicium, titanium or zirconium oxide.