PURPOSE: To easily produce each of the compounds, which is useful as a raw material for preparing a specific molecule that has therapeutically useful properties, with economical advantage by subjecting the corresponding alkyl lactate to controlled oxidation under specified conditions.

CONSTITUTION: In this production, such an alkyl pyruvate represented by the formula CH3-CO-COOR (R is a 1-8C alkyl group), is produced by oxidizing the corresponding alkyl lactate represented by the formula CH3-CHOH-COOR, with a hydrogen peroxide aq. solution in the presence of a catalytic amount of bromine. At this time, the molar ratio of hydrogen peroxide to the alkyl lactate is 1 to 1.2 and bromine is used in such an amount as to provide a 10 to 200 mmol./mol. (bromine)/(alkyl lactate) ratio. This oxidation reaction is performed in an organic solvent such as dichloromethane, at 15 to 30°C and preferably, in the presence of visible or near ultraviolet rays of 250 to 700 nm wavelengths.