7-isopropylidene-2,3-diazabicyclo<2.2.1>hept-2-ene

5-propan-2-ylidenebicyclo[2.1.0]pentane

7,7-Dimethyl-3a,3b,4,5,7,7a-hexahydro-pentaleno[1,2-c]furan-1,3-dione

4,5,6,7-tetrachloro-3a,7a-dihydro-2-benzofuran-1,3-dione

(+-)-(4ar,6ac)-1,2,3,4,4a,5,6,6a,7,8-decahydro-1t,4t-etheno-benzo[c]phenanthrene-2t,3t,5t,6t-tetracarboxylic acid-2,3,5,6-dianhydride