Reaction of diphenylcarbonate (2) with enolized phenylmalonyl heterocyclic compounds as the quinolones 1 a-c, the quinolizinones 4 or the phenalenones 6 a, b yields the condensed isocoumarines 3 a-c, 5 or 7 a, b, respectively. Contrary to these results 3-hydroxy-2-phenyl-chinchonic acid (8) or its decarboxylated product 10 do not form the expected isocoumarin 9 but afford the diquinolino-γ-pyrone 11
二苯
碳酸酯(2)与烯醇化苯马来酰
杂环化合物如
喹诺酮1a-c、
喹诺酮4或苯并酮6a、b反应,分别得到缩合异
咖啡因3a-c、5或7a、b。与这些结果相反,3-羟基-2-苯基-奎奴酸(8)或其脱羧产物10不形成预期的异
咖啡因9,而是产生二
喹啉基-
γ-吡喃酮11。