1,2,3,4-Cyclopentanetetracarboxylic acid, (1alpha,2alpha,3alpha,4alpha)- 3786-91-2 AI3-50868 CIS-CYCLOPENTANETETRACARBOXYLIC ACID EINECS 223-256-7 r-1,c-2,c-3,c-4-Cyclopentanetetracarboxylic acid