Process for Producing Cyclopentanone-2, 3, 5-Tricarboxylic Acid Triester

A process for producing a cyclopentanone-2,3,5-tricarboxylic acid triester represented by the general formula (IV):

• wherein R5, R6, and R7 each independently represents an alkyl group which may have a substituent;
• the process comprising:
• (1) allowing an itaconic acid diester represented by the general formula (I):
• wherein R1 and R2 each independently represents an alkyl group which may have a substituent;
• to react with a metal salt of malonic acid diester represented by the general formula (II):
• wherein R3 and R4 each independently represents an alkyl group which may have a substituent, and M represents an alkali metal;
• to obtain a reaction mixture containing an adduct represented by the general formula (III):
• wherein R1, R2, R3, R4, and M are as defined above;
• and then
• (2) allowing said reaction mixture without isolating the adduct (III) from said reaction mixture to react with an alcohol and a metal alkoxide mixture to form the cyclopentanone-2,3,5-tricarboxylic acid triester represented by the general formula (IV).