1,2,3,4-tetrachloro-1,4,4a,8a-tetrahydro-1,4-methanonaphthalene-5,8-dione

1-chloro-4-[(2,3,4,5-tetrachlorocyclopenta-2,4-dien-1-ylidene)methyl]benzene

2-[(2,3,4,5-tetrachlorocyclopenta-2,4-dien-1-ylidene)methyl]furan

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

1,2,3,4-tetrachloro-5-ethylidenecyclopenta-1,3-diene