戊烷二酰胺

cyclohexyl 4-oxopentanoate

3-(2-phenylethenyl)-4,5-dihydro-1H-pyridazin-6-one

(E)-6-(2-hydroxyphenyl)-4-oxohex-5-enoic acid

(2,5-dioxopyrrolidin-1-yl) 4-oxopentanoate