Process for the preparation of novel, optionally substituted, succinaldehyde monoacetals

摘要

Novel, optionally substituted, succinaldehyde monoacetals of the formula I IMAGE in which R1 is hydrogen, alkyl with 1 to 10 carbon atoms, cycloalkyl with 5 to 7 carbon atoms or unsubstituted or alkyl-substituted phenyl; R2 is alkyl with 1 to 4 carbon atoms or phenyl; R3 is alkyl with 1 to 4 carbon atoms; and furthermore R2 and R3 together are an optionally alkyl-substituted ethylene group, are prepared with the aid of a novel process starting from corresponding alpha , beta -unsaturated aldehydes which are substituted in the gamma position by halogen or an alkyl- or aryl-sulphonyloxy group. This entails introducing the aldehyde into the solution of an alkali metal alkanolate with 1 to 4 carbon atoms, of an optionally alkyl-substituted alkali metal ethylene glycolate or of an alkali metal phenolate in an alkanol with 1 to 4 carbon atoms in such a way that the temperature of the reaction mixture does not exceed 50 DEG C, then allowing the reaction mixture to react completely. The novel succinaldehyde monoacetals are of great interest as intermediates for the preparation of perfumes and of terpene derivatives of the juvenile hormone type.