5-phenyl-8-oxabicyclo[3.2.1]oct-6-en-3-one

8-(4-methylphenyl)sulfonyl-8-azabicyclo[3.2.1]oct-6-en-3-one

methyl 3-oxo-8-azabicyclo[3.2.1]oct-6-ene-8-carboxylate

甲基2-乙基-3-氧代-8-氮杂双环[3.2.1]辛-6-烯-8-羧酸酯