(R)-2-[(R)-2-(tert-Butoxycarbonyl-methyl-amino)-4-methyl-pentanoylamino]-3-(4-fluoro-3-nitro-phenyl)-propionic acid

[(R)-1-((8R,11S,14R)-8-Hydroxymethyl-11-methyl-18-nitro-10,13-dioxo-2-oxa-9,12-diaza-tricyclo[14.2.2.13,7]henicosa-1(19),3(21),4,6,16(20),17-hexaen-14-ylcarbamoyl)-3-methyl-butyl]-methyl-carbamic acid tert-butyl ester

{(R)-1-[(R)-1-{(S)-1-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-1-(3-hydroxy-phenyl)-ethylcarbamoyl]-ethylcarbamoyl}-2-(4-fluoro-3-nitro-phenyl)-ethylcarbamoyl]-3-methyl-butyl}-methyl-carbamic acid tert-butyl ester