methyl 1-acetyl-2-ethenylcyclopropane-1-carboxylate

methyl 1-acetylcyclopent-3-ene-1-carboxylate

methyl 2-ethenyl-5-methyl-2,3-dihydrofuran-4-carboxylate

环戊-3-烯-1,1-二甲酸二叔丁酯

di-tert-butyl 2-vinylcyclopropane-1,1-dicarboxylate