[(S)-3-Diazo-2-oxo-1-((S)-2-oxo-pyrrolidin-3-ylmethyl)-propyl]-carbamic acid tert-butyl ester

[(S)-3-Azido-2-oxo-1-((S)-2-oxo-pyrrolidin-3-ylmethyl)-propyl]-carbamic acid tert-butyl ester

[(S)-3-(1,4-Dioxo-3,4-dihydro-1H-phthalazin-2-yl)-2-oxo-1-((S)-2-oxo-pyrrolidin-3-ylmethyl)-propyl]-carbamic acid tert-butyl ester

2-[(S)-3-Amino-2-oxo-4-((S)-2-oxo-pyrrolidin-3-yl)-butyl]-5-nitro-2,3-dihydro-phthalazine-1,4-dione