(2S)-2-(trityloxymethyl)-2H-furan-5-one

2,3-O-(ethoxymethylene)-D-ribonic acid γ-lactone

(E)-3-(2,2-二甲基-[1,3]二氧杂烷-4-基)-丙烯酸乙酯

[(2S)-5-oxo-2H-furan-2-yl]methyl acetate

methyl (Z)-3-(2,2-dimethyl-1,3-dioxolan-4-yl)-2-propenoate