(2R,3S,4R,5S)-N-(tert-butoxycarbonyl)-2-formylmethyl-3,4-O-isopropylidene-5-methylpyrrolidine-3,4-diol

(2R,3S,4R,5S)-N-(tert-butoxycarbonyl)-2-ethoxycarbonylmethyl-3,4-O-isopropylidene-5-methylpyrrolidine-3,4-diol

(2R,3S,4R,5S)-N-(tert-butoxycarbonyl)-2-(2-aminophenyl)carbamoylmethyl-3,4-O-isopropylidene-5-methylpyrrolidine-3,4-diol

(3aS,4R,6S,6aR)-4-(2-Hydroxy-ethyl)-2,2,6-trimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyrrole-5-carboxylic acid tert-butyl ester

(2R,3S,4R,5S)-N-(tert-butoxycarbonyl)-2-(1H-benzimidazol-2-ylmethyl)-3,4-O-isopropylidene-5-methylpyrrolidine-3,4-diol