NOVEL PROCESS FOR THE MANUFACTURE OF GAMMA,DELTA-UNSATURATED KETONES

The present invention is directed towards an industrial sustainable process for the manufacture of gamma, delta-unsaturated ketones of formula (III ) in the presence of novel catalysts of formula (IV), wherein R1 is methyl or ethyl, R3 is methyl, R2 is a saturated or unsaturated linear, branched or cyclic hydrocarbyl group with 1 to 46 C atoms, and R and R' are independently from each other selected from the group consisting of linear C1-6-alkyl, branched C3-6-alkyl, aryl and aralkyl (see also Fig.1). The present invention is especially directed towards an industrial sustainable process for the manufacture of 6-methyl-5-hepten-2-one ("MH"; see Fig. 2), 6-methyl-5-octen-2-one ("EH"; see Fig. 3), (5EZ)-6, 10-dimethyl- 5,9-undecadien-2-one (f)-geranylacetone = "GA"; (Z)-nerylacetone = "NA"; see Fig. 4), (5fZ)-6, 10-dimethyl-5-undecen-2-one ((f)-dihydrogeranyl- acetone = "DHGA"; (Z)-dihydronerylacetone = "DHNA"; see Fig. 5) and 6, 10, 14-trimethyl-5,9, 13-pentadeca-trien-2-one (= farnesylacetone; "FA"; see Fig. 6). Preferred catalysts according to the present invention are "DPPI" (diphenyl phosphite), "DMPI" (dimethyl phosphite) and "DBPI" (dibenzyl phosphite).