Patent ID: 7161041

Claim:
A process for producing a 2-(1-hydroxyalkyl)cycloalkanone and/or a 2-(1-hydroxyaryl)cycloalkanone represented by formula (3), which comprises the steps of subjecting a cycloalkanone, and an aldehyde represented by formula (2) comprising a carboxylic acid represented by formula (1), to aldol condensation in the presence of water and a basic catalyst, wherein the molar amount of the basic catalyst A added is not less than the molar amount of the carboxylic acid (1) represented by the formula (1) B and the difference between A and B is 0.06 mol or less per mol of the aldehyde (2) wherein n is an integer of 1 or 2, and R 1 represents a hydrogen atom or a C1 to C8 linear or branched alkyl group or a substituted or unsubstituted aryl group wherein an aqueous layer obtained after the aldol condensation reaction is used again, wherein an aqueous layer recovered through pH adjustment with an acid and separation of the layer after the aldol condensation reaction is used again.