Patent ID: 8507718

Claim:
A method for reducing a content of an impurity in a ketocarboxylic acid composition comprising at least 1 wt % of the impurity and a ketocarboxylic acid I wherein R 2 is C 1 -C 6 alkyl and a=0-3, the method comprising: contacting a hydrocarbon polyol II G-[OH] t II wherein G is a hydrocarbyl group having a valence oft, and t=2-3, with the ketocarboxylic acid composition in an esterification reaction mixture wherein the ketocarboxylic acid I is present in an amount of at least 0.75 equivalents of the ketocarboxylic acid I per one equivalent of hydroxy group in the hydrocarbon polyol II, under conditions effective to form a ketocarboxylic ester III wherein R 2 is C 1 -C 6 alkyl, a=0-3, y=2-3 and z=0-1, provided that z+y=t; and isolating the ketocarboxylic ester III from the esterification reaction mixture.