dimethyl 2-(5-methylthiophen-2-yl)propanedioate

dimethyl 2-(1H-pyrrol-2-yl)propanedioate

甲基5-甲氧基-2-苯基-1,3-恶唑-4-羧酸酯

dimethyl 2-ethenyl-2-methylcyclopropane-1,1-dicarboxylate

methyl 5-methoxy-2-methyl-1,3-oxazole-4-carboxylate