Disclosed is a method of making an insulinotropic peptide, comprising the following steps of a) to f): a) providing a first peptide fragment including the amino acid sequence HX8EX10 (SEQ ID NO.6), wherein X8 and X10 are each residues of an achiral amino acid, each of H and E optionally including side chain protection； b) providing a second peptide fragment including the amino acid sequence TFTSDVXI7-18YLEG (SEQ ID NO.8) wherein the residue denoted by the symbol XI7-18 is a dipeptide residue of a pseudoproline, said amino acid residues of the sequence optionally including side chain protection； c) coupling the first fragment to the second fragment to provide a third peptide fragment including the amino acid sequence HX8EX10 TFTSDVXI7-18YLEG (SEQ ID NO. 11), said amino acid residues of the sequence optionally including side chain protection； d) providing a fourth peptide fragment including the amino acid sequence QAAKEFIAWLVKX35 (SEQ ID NO.9), wherein X35 is a residue of an achiral amino acid, said amino acid residues of the sequence optionally including side chain protection； e) coupling the fourth peptide fragment to arginine in order to provide a fifth peptide fragment including the amino acid sequence QAAKEFIAWLVK X35R (SEQ ID NO. 12), said residues of the sequence optionally including side chain protection； and f) coupling the fifth fragment to the third fragment in order to provide an insulinotropic peptide including the amino acid sequence HXSEXIOTFTSDVXI7-18 YLEGQAAKEFIAWLVK X35R (SEQ ID NO. 13), said residues of the sequence optionally including side chain protection.
