PURPOSE: To obtain a 2-oxyfatty acid useful as a raw material for surfactants, cosmetic bases, water-soluble antioxidants, water) soluble antimicrobial agents, medicinal stocks, specialty chemicals, etc., by substitution reaction between a halofatty acid alkali metal salt and an alcohol.

CONSTITUTION: This compound of formula R1CH(OR2)COOH (e.g. 2- methoxybutanecarboxylic acid, 2-ethoxyoctanecarboxylic acid) is obtained by reaction between a 2-halofatty acid alkali metal salt of formula R1CH(X)COOH (R1 is an alkyl, alkenyl, etc.; X is a halogen) and an alcohol of formula R2OH (R2 is an alkyl, cycloalkyl, alkenyl, heterocyclic aromatic group, etc.).