2-propan-2-ylidenebicyclo[3.1.0]hex-3-ene-6-carboxylic acid

ethyl 2,2-dimethylspiro[2.4]hepta-4,6-diene-1-carboxylate

5-(3-cyclopenta-2,4-dien-1-yl-2,3-dimethylbutan-2-yl)cyclopenta-1,3-diene

2-isopropylcyclopentadiene

5-propan-2-ylcyclopenta-1,3-diene