SEARCH Articles Figures Tables 1,3 -dihydro-1,3 -dioxo-5 -isobenzofurancarboxylic acid 1//-Pyrroles, 4,5-dioxo-4,5-dihydro 2,5-Dihydro-2,5-dioxo-3-methyl-3-pyrrole 2,5-Dioxo-7-nitro-3,4-dihydro 2.4- Dioxo 3,7-Dioxo-6-methyl-3,7-dihydro 5.6- Dihydro-5,6-dioxo pyrazine