3,5-dioxo-5-pyridin-3-yl-pentanoic acid ethyl ester

5-hydroxy-3-oxo-5-pyridin-3-yl-pent-4-enoic acid ethyl ester

烟酸乙酯

3,5-dioxo-5-[3]pyridyl-valeric acid

N,N'-羰基二咪唑