PURPOSE: To obtain the titled compound in high yield, by reacting o-(allyloxy) chlorobenzene with an α-(alkylsulfinyl)acetic ester, followed by reduction and hydrolysis.

CONSTITUTION: A compound shown by the formula I is reacted with a compound shown by the formula II (R1 is alkyl; COOR2 is esterified carboxyl), to give a novel compound shown by the formula III. The reaction is carried out in the presence of a proton acid, e.g., p-tolune-sulfonic acid, etc. This compound is subjected to reductive desulfuration using a reducing agent, e.g., zinc powder and acetic acid to give a compound shown by the formula VI. And, if necessary, this compound is hydrolyzed and converted into an acid shown by the formula VI'. Since sodium cyanide is not used, this method is advantageous with respect to prevention of environmental pollution.