Verfahren zur Herstellung von alpha,beta-ungesättigten Aldehyden.

摘要

A process for preparing alpha , beta -unsaturated aldehydes of the general formula (I) (I) in which R1, R2 and R3 are independently a hydrogen atom, or an alkyl or alkenyl group with or without being substituted with a lower acyloxy group. The aldehyde of the general formula (I) is prepared by reaction between an allylic chloride of the following general formula (IIa) (IIa) in which R1, R2 and R3 have, respectively, the same meanings as defined above, and an amine oxide selected from the group consisting of tri(lower alkyl)amine N-oxides of the formula, R34N+O-, in which R4 represents a lower alkyl group having from 2 to 4 carbon atoms, and N-lower alkylmorpholine N-oxides of the following formula in which R5 represents a lower alkyl group having from 1 to 4 carbon atoms. Alternatively, the aldehyde of the formula (I) is obtained by reaction between an allylic chloride of the following general formula (IIb) (IIb) in which R1, R2 and R3 have, respectively, the same meanings as defined above, and an amine oxide selected from the group consisting of tri(lower alkyl)amine N-oxides of the formula, R34N+O-, in which R4 has the same meaning as defined above, and N-lower alkylmorpholine N-oxides of the following formula in which R5 has the same meaning as defined above, in the presence of an alkali metal iodide or a copper halide.