PURPOSE: To easily obtain in high yield the subject compound useful as an intermediate for pesticides and medicines by reaction of a specific ester with a ketone in the presence of a phase-transfer catalyst and an acid scavenger.

CONSTITUTION: The objective compound of formula III can be obtained by reaction of (A) a compound of formula I (Z is alkyl) (e.g. methyl-fluorosulfonyl acetate) with (B) a compound of formula II [R is alkyl, cycloalkyl, (substituted) phenyl, (substituted) phenylalkyl, (substituted) phenylalkenyl, heteroaryl or condensed aromatic ring] (e.g. phenacyl bromide) in the presence of (C) a phase- transfer catalyst (e.g. dimethylammonium benzyl chloride) and (D) an acid scavenger (e.g. sodium bicarbonate, triethylamine).