Process for producing β,γ-unsaturated aldehyde

Claim 1

A process for preparing β, γ- unsaturated aldehyde having the formula ##STR5## wherein R 1 is selected from the group consisting of alkyl having 1 to 12 carbon atoms, phenyl, ##STR6## CH 2 ═CH(CH 2 ) 7 -- and cyclohexyl, and R 2 is selected from the group consisting of allyl, crotyl, methyallyl, 2-methylcrotyl, prenyl, 2,3-dimethylcrotyl, 2-heptenyl, 4,4-dimethyl-2-pentenyl, 2-chloroallyl, 3-chloroallyl, 2-bromoallyl, 2-methyl-3-chloroallyl, 3-chloro-2-pentenyl, cinnamyl, geranyl, propynyl, 2-butynyl, 1-butynyl, 2-pentynyl, 2-hexynyl, 2-heptynyl, 1-phenylpropynyl, 4-chloro-2-butynyl, benzyl, methylphenylmethyl, ethylphenylmethyl, isopropylphenylmethyl, fluorophenylmethyl, chlorophenylmethyl, bromophenylmethyl, iodophenylmethyl, hydroxyphenylmethyl, methoxymethylphenyl, phenoxyphenylmethyl, nitrophenylmethyl, cyanophenylmethyl, acetylphenylmethyl and α-methylnaphthalene, which comprises: admixing and vigorously stirring, at a temperature of from 10° to 150° C., (A) an aldehyde having the formula R 1 --CH 2 --CHO, with (B) a halide having the formula R 2 X, wherein X is halogen, at a molar ratio of A:B in the range of from 2:l to 10:1, in an aqueous solution of an alkaline material selected from the group consisting of alkali metal and alkaline earth metal hydroxides, carbonates and bicarbonates wherein the amount of said alkaline material is a molar excess relative to B, and in the presence of an organic quaternary ammonium salt effective as a phase transfer catalyst and present in an amount of not more than 0.5 mole per mole of A and effective to catalyse the reaction of A and B whereby to form said β, γ-unsaturated aldehyde, and recovering said β, γ-unsaturated aldehyde from the reaction mixture.