(5E,7R,8R,9S,10S)-7,9:8,10-di-O-isopropylidene-7,8,9,10-tetraoxotridec-5-enoic acid tert-butyl ester

(5R,6R,7R,8R,9S,10S)-5,6-dihydroxy-7,9:8,10-di-O-isopropylidene-7,8,9,10-tetraoxotridecanoic acid tert-butyl ester

(5R,6S,7R,8R,9S,10S)-5,6-dihydroxy-7,9:8,10-di-O-isopropylidene-7,8,9,10-tetraoxotridecanoic acid tert-butyl ester

(5R,6R,7R,8R,9S,10R)-5,6-dihydroxy-7,8:9,10-di-O-isopropylidene-7,8,9,10-tetraoxotridecanoic acid tert-butyl ester

(5S,6R,7R,8R,9S,10R)-5,6-dihydroxy-7,8:9,10-di-O-isopropylidene-7,8,9,10-tetraoxotridecanoic acid tert-butyl ester