methyl 6-[(R)-(4-methylphenyl)sulfinyl]-3,5-dioxohexanoate

methyl 2-butyl-3,5-dioxohexanoate

(R)-6-甲基四氢吡喃-2-酮

4-hydroxy-7-methylpyrano[3,2-c]pyran-2,5-dione

3-乙基-4-羟基-6-甲基-2H-吡喃-2-酮