2678-54-8
1,1-二乙氧基乙烯
+
623-47-2
丙炔酸乙酯
→
~66%
76221-41-5
ethyl 4,4-diethoxycyclobutene-1-carboxylate
3377-20-6
甲撑丙二酸二乙酯
79745-83-8
ethyl 2-(diethoxymethylene)but-3-enoate