1,5,18,22-tetraoxacyclotetratriacontane-2,4,19,21-tetrone

4-hydroxy-7-methylpyrano[3,2-c]pyran-2,5-dione

1-butyl-1,3-diazinane-2,4,6-trione

(1,3-二氧代丙烷-1,3-二基)双氨基甲酸二乙酯

1,5-二氢苯并[b][1,4]二氮杂卓-2,4-二酮