2-acetyl-4-methylcyclopent-4-ene-1,3-dione

3-methyl-4-phenylfuran-2,5-dione

3-甲基-2,5-二吡咯烷酮

15-methyl-17-oxapentacyclo[6.6.5.02,7.09,14.015,19]nonadeca-2,4,6,9,11,13-hexaene-16,18-dione