3-(but-3-enoylamino)-N-(1,3-thiazol-2-yl)pyridine-2-carboxamide

5-氧代戊酸甲酯

methyl 3-methyl 4-oxobutanoate

buta-1,3-dien-1-one

(2,2-dimethyl-1,3-dioxolan-4-yl)methyl but-3-enoate