PRODUCTION OF BETA-HYDROXYCARBOXYLIC ACID DERIVATIVE

PURPOSE:To permit safe and advantageous production of the subject compound which is used as a synthetic intermediate of medicines and agrochemicals by using a specific cobalt complex as a catalyst to allow readily available alpha,beta-unsaturated carboxylic acid to react with a carbonyl compound and a phenylsilane. CONSTITUTION:A cobalt complex of a beta-dicarbonyl compound of formula I (R , R , R and R are independent to one another and 1 to 10C lower alkyl, cycloalkyl, aryl; R , R are independent mutually and lower alkyl, aryl, arylalkyl) is used as a catalyst to effect reaction between an alpha,beta-unsaturated carboxylic acid derivative of formula II (R , R , R are independent to one another and lower alkyl of 1 to 10 carbon atoms; X is H, lower alkoxy of 1 to 10 carbon atoms, phenoxy), a carbonyl compound of formula III (R , R are H, alkyl of 1 to 20 carbon atom) and phenylsilane. After reaction, phenylsilane is preferably eliminated by hydrolysis or solvolysis to give the compound of formula IV.