The 14-membered imide 1 reacts with different isocyanates to the [n+2]-Zip ring-enlargement products 2a-d in high yields. These 16-membered heterocycles can be regarded as macrocyclic analogues of barbituric acid. Using the more reactive phenyl isocyanate the twofold ring-enlarged 18-membered compound 5 was formed.
14 元
亚胺 1 与不同的
异氰酸酯反应生成高产率的 [n+2]-Zip 环扩大产物 2a-d。这些 16 元杂环可视为
巴比妥酸的大环类似物。使用反应性更强的
异氰酸苯酯,可以生成双倍环扩大的 18 元化合物 5。