(2S,4R)-((Z)-4-Propenyl)-pyrrolidine-1,2-dicarboxylic acid 2-[(1R,2R)-2-allyloxycarbonyl-1-methyl-2-(4-methyl-benzyloxycarbonylamino)-ethyl] ester 1-tert-butyl ester

[5-sec-butyl-18-methyl-11-(2-nitro-cyclopropylmethyl)-4,7,10,13,16,20-hexaoxo-8,14-bis-(1-phenyl-ethyl)-2-propenyl-octadecahydro-19-oxa-3a,6,9,12,15-pentaaza-cyclopentacyclononadecen-17-yl]-carbamic acid 4-methyl-benzyl ester