5-(tert-butyl-dimethylsilyl)oxy-7-[(3aS,4R,5S,6aR)-5-(tert-butyldimethylsilyl)oxy-2-oxo-hexahydro-cyclopenta[b]furan-4-yl]-hept-6-enoic acid methyl ester

(3aS,4R,5S,6aR)-methyl [5-(tert-butyldimethylsilyl)oxy-2-oxohexahydro-cyclopenta[b]furan-4-yl]acetate

[3-(tert-butyl-dimethylsilyl)oxy-2-carboxymethyl-5-oxo-cyclopentyl]acetic acid

(3aS,4R,5S,6aR)-hexahydro-5-(tert-butyldimethylsilyl)oxy-4-(2-hydroxy-ethyl)-cyclopenta[b]furan-2-one

(3aS,4R,5S,6aR)-[5-(tert-butyldimethylsilyl)oxy-2-oxo-hexahydro-cyclopenta[b]furan-4-yl]acetic acid