Production of high molecular weight α,β-unsaturated aldehydes

Claim 1

A process for the production of high molecular weight α,β-unsaturated aldehydes of the general formula (I): ##EQU7## where R 1 is hydrogen, alkyl of one to four carbon atoms, phenyl or phenyl bearing alkyl of one to four carbon atoms as a substituent; R 2 is hydrogen, alkyl of one to four carbon atoms, phenyl or phenyl bearing alkyl of one to four carbon atoms as a substituent; R 3 is hydrogen or alkyl of one to four carbon atoms; R 5 is hydrogen or alkyl of one to four carbon atoms; R 6 is hydrogen or alkyl of one to four carbon atoms; R 7 is hydrogen or alkyl of one to four carbon atoms; R 4 is hydrogen or a saturated or unsaturated, branched or linear aliphatic or cycloaliphatic hydrocarbon radical of one to twelve carbon atoms; R 8 is alkyl of one to four carbon atoms or (when R 9 is phenyl) hydrogen; and R 9 is a saturated or unsaturated branched or linear aliphatic or cycloaliphatic hydrocarbon radical of one to twelve carbon atoms, or phenyl wherein an allyl compound of the formula (II): ##EQU8## in which R 5 to R 9 have the meanings given above and R 10 is hydrogen or acyl of a carboxylic acid of one to five carbon atoms is reacted in the liquid phase with an α,β-unsaturated aldehyde of the formula (III): ##EQU9## in which R 1 to R 4 have the meanings given above, at elevated temperature of about 60°-300°C and in the presence of an acid catalyst wit a pK value of -9 to 6 in such an amount of such acid catalyst that the reaction mixture has a pH of 1 to 7.