5-氧代-己酸甲酯

4-乙酰基丁酸乙酯

5-((3S)-1,3-dihydroxybutylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione

5-(1-hydroxy-3-oxobutylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione

(S)-3-(1,3-dihydroxybutylidene)-1,5-dioxaspiro[5.5]undecane-2,4-dione