2,3-PENTADIENE,1,5-DIOIC ACID,DIMETHYL ESTER 2,3-pentadienedioic acid, dimethyl ester InChI=1/C7H8O4/c1-10-6(8)4-3-5-7(9)11-2/h4-5H,1-2H dimethyl penta-2,3-dienedioate