(R)-2-tert-Butoxycarbonylamino-pentanedioic acid 1-(3,5-dioxo-4-aza-tricyclo[5.2.1.02,6]dec-8-en-4-yl) ester 5-methyl ester

(R)-4-({[(S)-2-(N'-Acetyl-hydrazino)-1-benzyl-2-oxo-ethylcarbamoyl]-methyl}-carbamoyl)-4-tert-butoxycarbonylamino-butyric acid methyl ester