PURPOSE: To obtain the subject compound and enable selective introduction of various substituents at specific position of a phenol by reacting an acetic acid dienyl ester with carbon monoxide in the presence of a basic compound and an acid anhydride using a specific catalyst.

CONSTITUTION: The objective compound of formula II can be produced by reacting an acetic acid dienyl ester of formula I (R1 to R4 are H or 1-20C alkyl; R1 may be 6-20C aromatic group or 7-20C aralkyl which may have hetero atom in the aromatic ring) with CO in the presence of a basic compound (especially tertiary amine) and an acid anhydride (especially acetic anhydride) using a compound of Pd, Pt or Ru as a catalyst at 40-250°C (preferably 60-200°C) under a pressure of preferably 10-150 atm. Since the obtained compound can easily be converted to phenolic compound by saponification, substituted phenols having various substituents at specific position of a phenol and difficult to be produced by conventional process can easily be produced by this process.