4-Pyrimidinecarboxylic acid, 6-amino-2-(3-amino-1-((3-amino-2-(((1,1-dimethylethoxy)carbonyl)amino)-3-oxopropyl)amino)-3-oxopropyl)-5-methyl-, (S-(R*,R*))- 75452-30-1 Boc-pyrimidoblamic acid tert-Butyloxycarbonylpyrimidoblamic acid