二甲基双环[2.2.1]-2,5-庚二烯-2,3-二羧酸

2-重氮丙烷

2-cyclopropyl-2-methoxy-5,5-dimethyl-Δ3-1,3,4-oxadiazoline

丁炔二酸二甲酯

dimethyl 7-oxabicyclo[2.2.1]hepta-2(3),5(6)-diene-2,3-dicarboxylate