Synthesis of hEPO(79–166) Glycopeptide, 24.a
aKey: (a) 1. 6 M Gn•HCl, 100 mM NaH2PO4, 50 mM TCEP, pH 7.5, 67%; 2. piperidine, DMSO, 61%; 3. 0.2M MeONH2, 60%; (b) 6 M Gn•HCl, 100 mM NaH2PO4, 50 mM TCEP, pH 7.5, 23%; (c) 6 M Gn•HCl, 100 mM NaH2PO4, 50 mM TCEP, 200 mM MPAA, pH 7.8, 40%; (d) TCEP, VA-044, tBuSH. Ar = 2-(ethyldithio)-phenyl; R = CH2CH2CO2Et; VA-044 = 2,2’-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride