L-2,3-trans-3,4-cis-4,5-trans-N-(tert-butoxycarbonyl)-5-hydroxymethyl-3,4-isopropylidenedioxyproline

(+)-7-tert-butoxycarbonyl-2-[[(tert-butyl)dimethylsilyl]oxy]-5,6-exo-isopropylidenedioxy-7-azabicyclo[2.2.1]hept-2-ene

[((3aR,4S,6S,6aS)-6-Hydroxymethyl-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyrrole-4-carbonyl)-amino]-acetic acid benzyl ester

(3aR,4S,6S,6aS)-4-(Benzyloxycarbonylmethyl-carbamoyl)-6-hydroxymethyl-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyrrole-5-carboxylic acid tert-butyl ester

{[(3aR,4S,6S,6aS)-5-((S)-2-tert-Butoxycarbonylamino-3-phenyl-propionyl)-6-hydroxymethyl-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyrrole-4-carbonyl]-amino}-acetic acid benzyl ester