Diethyl 2,2-difluoro-4-methylenepentanedioate

9-((2-甲基-4-亚甲基-5-氧代四氢呋喃-2-基)甲基)次黄嘌呤

5'-methyl-5'-[(6-chloro-9H-purin-9-yl)methyl]-2'-oxo-3'-methylenetetrahydrofuran

2-羟甲基丙烯酸乙酯

diethyl 2,5-dimethylidenehexanedioate