3,6-Endoxo-.delta.'-tetrahydrophthalic anhydride 3,6-Epoxy-1,2,3,6-tetrahydrophthalic anhydride 4,7-Epoxyisobenzofuran-1,3-dione, 3a,4,7,7a-tetrahydro- 5426-09-5 7-Oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride Furan-maleic anhydride Diels-Alder adduct Furan-maleic anhydride adduct Furan-maleic anhydride copolymer NSC231495