side chains on the anthraquinone core (6b). Mild base treatment of 15 initiated successive aldol condensations to produce the benzo[a]naphthacenequinone 16 regioselectively in one operation. Deprotection of 16 afforded the antibiotic G-2A (1) and decarboxylation of 1 lead to G-2N (2).
通过在
蒽醌核心(6b)上连接两个相邻的C-4和C-6酮化物侧链来制备三氧杂酸酯15。在一次操作中,对15的轻度碱处理会引发连续的醛醇缩合反应,从而区域选择性地生成苯并[ a ]
萘并苯醌16。脱保护16得到抗生素G-2A(1),脱羧1得到G-2N(2)。