Processes for preparing 2-('omega'-alkoxycarbonylalkanoyl)-4-butanolides, 'omega'-hydroxy-('omega'-3)-keto fatty esters, and derivatives thereof

In industrial production of omega -hydroxyaliphatic acid being an important intermediate for large cyclic lactone-based perfumes, using dicarboxylate ester which is inexpensive and readily obtainable, a method, with high yield and improved selectively, for making a 2-( omega -alkoxycarbonylalkanoyl)-4-butanolide and an alkaline metal salt thereof, an ester of omega -hydroxy-( omega -3)-ketoaliphatic acid as a novel compound and a derivative thereof, and a method for making the same are provided. Condensation reaction of gamma -butyrolactone with a dicarboxylate ester represented by the general formula (1) ROOC(CH2)nCOOR wherein n is an integer of 7 to 13 and R is an alkyl group forms a condensation solution containing an alkaline metal salt of 2-( omega -alkoxycarbonylalkanoyl)-4-butanolide represented by the general formula (3): wherein n is an integer of 7 to 13, R is an alkyl group, and M is an alkaline metal; the solution is extracted with water or an aqueous alkaline solution and subjected to hydrolysis and decarboxylation to form an alkaline metal salt of omega -hydroxy-( omega -3)-ketoaliphatic acid represented by the general formula (5): wherein n is an integer of 7 to 13 and M is an alkaline metal; and the compound is selectively and effectively separated and recovered and then acidified to form an omega -hydroxy-( omega -3)-ketoaliphatic acid represented by the general formula (10): wherein n is an integer of 7 to 13.a