PURPOSE: To suppress the dissolution of the catalyst in the aqueous phase in the preparation of the titled compound, by hydroformylating vinyl acetate in the presence of a catalyst, treating the reaction liquid in an organic solvent with a gaseous mixture of hydrogen and carbon monoxide having specific partial pressure and molar ratio, and extracting the treated liquid with an aqueous medium.

CONSTITUTION: Vinyl acetate is hydroformylated with a mixture of hydrogen and carbon monoxide in an organic solvent in the presence of an essentially water-insoluble rhodium complex, preferably a HRh(CO)(PA3)3 (A is aryl) complex and trisubstituted phosphine. The resultant reaction mixture is brought into contact with a gaseous mixture of hydrogen and carbon monoxide having a partial CO pressure of 0.2W10abs. atm, a partial H2 pressure of 1W5abs. atm and a molar ratio (H2/CO) of 1W20, at 50W100°C (usually for 10W90min). The treated liquid is extracted with an aqueous medium to extract the objective compound to the aqueous layer. The residual oil layer containing the catalyst component is recycled and reused.