Furan-2,3,4- -trione

Benzenediamine (358) and 5-(l,2-dihydroxyethyl)tetrahydro-2,3,4-furane-trione (359) (prepared in situ by oxidation of ascorbic acid with p-benzoqui-none) gave either 3-(2,3,4-trihydroxybutyryl)-2(17i)-quinoxalinone (360)... 

Another furan precursor 161 has been used to generate a series of pyrrolo[2,3-rf]pyrimidine triones 162 (Equation 60) the furandiones react with aryl isocyanates, releasing 2 mol of carbon dioxide, to form compounds 162a-f <2004ASJ877>. 

Coned. H2SO4 added at 0° under anhydrous conditions to 2,3-dihydrophenalene-1,2,3-trione hydrate in abs. benzene, and stirred 4 hrs. at room temp. 7-oxo-7H-benzo[b]phenaleno[2,l-d]furan. Y 85%. A. Schonberg and M. Mamluk, B. 105, 1562 (1972). 

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