6-(chloromethyl)-1,5-dimethyl-3-oxabicyclo[3.2.0]heptane-2,4-dione

4,5-dimethylcyclopent-4-ene-1,3-dione

3,4-二甲基吡咯-2,5-二酮

Chaetomellic Acid A Anhydride

1-but-3-enyl-3,4-dimethylpyrrole-2,5-dione