(5S)-5-(hydroxymethyl)-5H-furan-2-one
2,3-O-ethoxymethylene-5-O-toluenesulfonyl-D-ribonolactone
5-O-{2,6-di-tert-butyl-4-[1-(3,5-di-tert-butyl-4-hydroxy-phenylsulfanyl)-1-methyl-ethylsulfanyl]phenyl}-2,3-O-(ethoxymethylene)-D-ribonic acid γ-lactone
2,3-dideoxy-5-O-(triphenylmethyl)-D-glycero-pent-2-enono-1,4-lactone
(S)-(5-oxo-2,5-dihydrofuran-2-yl)methyl 4-methylbenzenesulfonate