Organic tertiary or quaternary ammonium salts as catalysts in the formation of gamma, delta-unsaturated ketones

A process for the manufacture of gamma, delta-unsaturated ketones of the formula (I)

• by reaction of a compound of the formula (II) with a compound of the formula (IIIa) or (IIIb)
• in the presence of an organic tertiary or quaternary ammonium salt as catalyst;
• wherein
• R1 represents a methyl or ethyl group;
• R2 represents a saturated or unsaturated linear or branched or cyclic hydrocarbyl group with 1 to 46 C atoms;
• R3 represents a methyl or an ethyl group;
• R4 represents H or methyl or an ethyl group;
• R5 represents a linear or branched C1-10-alkyl group, particularly a methyl or an ethyl group;
• R5′ and R5″ represent
• either a linear or branched C1-10-alkyl group, particularly a methyl or an ethyl group;
• or R5′ and R5″ form together a linear or branched C1-10-alkylene group, particularly an ethylene or propylene group;
• and
• wherein the wavy line represents a carbon-carbon bond and which when linked to the carbon-carbon double bond is either in the Z or in the E-configuration.