6,7-bis(4-tolylsulfonyloxymethyl)-3-thiabicyclo(3.2.0)heptane 3,3-dioxide

1,2-bis(ethenyl)cyclobutene

bicyclo[4.2.0]octa-1,5-diene

5,6-dimethylidene-2,3-diazabicyclo[2.2.2]oct-2-ene

1'-acetoxy-bicyclobutyl-1-ene