1H-cyclopenta[c]furan-1,3(4H)-dione, 5,6-dihydro- 5,6-dihydro-1H-cyclopenta[c]furan-1,3(4H)-dione InChI=1/C7H6O3/c8-6-4-2-1-3-5(4)7(9)10-6/h1-3H