[(S)-1-((S)-1-{(S)-[(2R,3R)-2-((S)-1-Butylcarbamoyl-2-methyl-propylcarbamoyl)-1-methyl-5-oxo-pyrrolidin-3-yl]-hydroxy-methyl}-3-methyl-butylcarbamoyl)-3-methylsulfanyl-propyl]-carbamic acid tert-butyl ester

[(S)-1-((S)-1-{(S)-[(2S,3S)-2-((S)-1-Butylcarbamoyl-2-methyl-propylcarbamoyl)-1-methyl-5-oxo-pyrrolidin-3-yl]-hydroxy-methyl}-3-methyl-butylcarbamoyl)-3-methylsulfanyl-propyl]-carbamic acid tert-butyl ester