Abstract
Improved synthesis of fully protected hexadecapeptide Bpoc-Cys(Trt)-Cys-(Trt)-Thr(But)-Ser(But)-Ile-Cys(Trt)-Ser(But)-Leu-Tyr(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut, which corresponds to the amino acid sequence 71-86 of human proinsulin, is described. The final product was obtained by condensation of 3 fragments 71-74, 75-77 and 78-86.