((3R,3aS,4S,6aS)-4-((2R,3R)-3-(ethanoyloxy)-4-hydroxy-2-methylbutyl)-3a-hydroxy-1,3-dimethyl-2,6-dioxohexahydro-1H-furo[3,4-b]pyrrol-6a-yl)methyl ethanoate

((3R,3aS,4S,6aS)-4-((2R,3R)-3-(ethanoyloxy)-2-methyl-4-oxobutyl)-3a-hydroxy-1,3-dimethyl-2,6-dioxohexahydro-1H-furo[3,4-b]pyrrol-6a-yl)methyl ethanoate

(3R,3aS,4S,6aS)-4-{(2R,3R)-4-benzyloxy-2-methyl-3-[triethylsilyloxy]butyl}-3-methyl-6a-{[triethylsilyloxy]methyl}-3a-[trimethylsilyloxy]dihydro-1H-furo[3,4-b]pyrrole-2,6(3H,4H)-dione

(3R,3aS,4S,6aS)-4-((2R,3R)-4-(benzyloxy)-2-methyl-3-((trimethylsilyl)oxy)butyl)-3-methyl-6a-(((triethylsilyl)oxy)methyl)-3a-((trimethylsilyl)oxy)tetrahydro-6H-furo[3,4-b]pyrrole-2,6(3H)-dione