(E)-3-(2,2-二甲基-[1,3]二氧杂烷-4-基)-丙烯酸乙酯

methyl (S)-4,5-dihydroxy-4,5-O-isopropylidene-2-pentenoate

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

5-O-trityl-2-deoxy-D-erythro-pentono-1,5-lactone