To produce the subject compound useful as an intermediate for producing a synthetic antimicrobial agent according to a simpler method in a higher yield than those in a conventional method by reacting a specific carboxylic acid with propylene oxide in the presence of a specified metal complex catalyst.

A carboxylic acid represented by the formula: RCOOH (R is a 1-20C alkyl or the like) (e.g. benzoic acid or p-nitrobenzoic acid) is reacted with propylene oxide in the presence of a metal complex catalyst represented by the formula {R1 is a 1-20C alkylene or the like; X1 to X10 are each H, a halogen, an alkyl or the like; M is M1 (M1 is a bivalent metal atom or a bivalent metal ion), M2-A1 (M2 is a bivalent metal atom or a trivalent metal atom; A1 is a ligand) or M3-A2 (M3 is a trivalent metal ion; A1 is a counterion), preferably M1 and especially preferably when M1 is a bivalent cobalt atom [CoII]} to thereby afford the objective compound represented by the formula: CH3CH (OH)CH2OCOR.