24447-28-7 4,6-Etheno-1H-cycloprop[f]isobenzofuran-1,3(3aH)-dione, 4,4a,5,5a,6,6a-hexahydro- NSC90882 Tricyclo[3.2.2.02,4]non-8-ene-6,7-dicarboxylic anhydride