Patent ID: 7893294

Claim:
A process for production of a trans-2,2-dimethyl-3-formylcyclopropanecarboxylic acid ester comprising: (A) a step of reacting a trans-isomer of a 2,2-dimethyl-3-(acyloxymethyl)cyclopropanecarboxylic acid ester or a mixture of a trans- and cis-isomers thereof with at least one alkali metal compound selected from the group consisting of an alkali metal hydroxide, an alkali metal carbonate and an alkali metal alcoholate in the presence of an alcohol solvent to obtain a mixture containing a trans-2,2-dimethyl-3-(hydroxymethyl)cyclopropanecarboxylic acid ester, (B) a step of conducting an oxidation treatment of the mixture which contains a trans-2,2-dimethyl-3-(hydroxymethyl)cyclopropanecarboxylic acid ester and which is obtained in the above-mentioned step (A) to obtain a mixture containing a crude trans-2,2-dimethyl-3-formylcyclopropanecarboxylic acid ester, (C) a step of contacting the mixture obtained in the above-mentioned step (B) with an aqueous alkali metal hydrogen sulfite solution to obtain an alkali metal salt of a trans-2,2-dimethyl-3-[(hydroxy)(sulfo)methyl]cyclopropanecarboxylic acid ester, and (D) a step of contacting the alkali metal salt obtained in the above-mentioned step (C) with an acid, a base or a water-soluble aldehyde to obtain a trans-2,2-dimethyl-3-formylcyclopropanecarboxylic acid ester.