Peramivir Impurity 1 methyl (3aS,4R,6S,6aR)-4-((tert-butoxycarbonyl)amino)-3-(pentan-3-yl)-3a,5,6,6a-tetrahydro-4H-cyclopenta[d]isoxazole-6-carboxylate Peramivir (1S-4R)-4-[[(1,1-diMethylethoxy)carbonyl]aMino]- 2-Cyclopentene-1-carboxylic acid Methyl ester (1S,4R)-Methyl 4-aMinocyclopent-2-enecarboxylate hydrochloride (1R,4S)-Methyl 4-aMinocyclopent-2-enecarboxylate (Hydrochloride) Peramivir Impurity 4 Trans-(1R,4R)-4-Boc-aMino-2-Cyclopentene-1-carboxylic acid Methyl ester Peramivir Impurity 2 methyl (S)-4-((tert-butoxycarbonyl)amino)cyclopent-1-ene-1-carboxylate Peramivir Impurity 34 Peramivir Impurity 7 HCl Peramivir Impurity 7 PeraMivir Methyl Ester IMpurity Peramivir Impurity 32 methyl (4R)-4-{[(tert-butoxy)carbonyl]amino}cyclopent-1-ene-1-carboxylate Peramivir Impurity 33 Peramivir Impurity 13