(S)-2-[((2R,3S,4R,5R)-3,4-Dihydroxy-5-hydroxymethyl-pyrrolidine-2-carbonyl)-amino]-3-methyl-butyric acid benzyl ester

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