"(2R,3R)-rel-1,2,3,4-Butanetetracarboxylic acid, 2,3-diMethyl ester"
"(2R,3R)-rel-1,2,3,4-Butanetetracarboxylic acid, 2,3-diMethyl ester"
"(2R,3R)-rel-1,2,3,4-Butanetetracarboxylic acid, 2,3-diMethyl ester"
"(2R,3R)-rel-1,2,3,4-Butanetetracarboxylic acid, 2,3-diMethyl ester"