(4S,5S)-isobutyl-5-methoxycarbonylethynyl-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester

(S)-2-((S)-2-{[(1R,2R)-2-((4S,5S)-3-tert-Butoxycarbonyl-4-isobutyl-2,2-dimethyl-oxazolidin-5-yl)-cyclopentanecarbonyl]-amino}-propionylamino)-pentanedioic acid dibenzyl ester