dimethyl (S)-2-[di(tert-butoxycarbonyl)amino]hexanedioate

N-α,N-ω,N'-ω'-tri-(t-butyloxycarbonyl)-L-arginine

(S)-(-)-methyl 2-[bis(tert-butoxycarbonyl)amino]-4-nitrobutanoate

(-)-methyl 4-(2S)-2-[bis(tert-butoxycarbonyl)amino]-3-(methoxy)-3-oxopropyl-1H-pyrrole-2-carboxylate

methyl 2-[bis(tert-butoxycarbonyl)amino]-5-acetoxy-4-nitropentanone