Azapeptides, peptide analogues in which the α-carbon of one or more of the amino acid residues is replaced with a nitrogen atom, exhibit propensity for adopting β-turn conformations. A general protocol for the synthesis of azapeptides without racemization on solid phase has now been developed by introducing the aza-amino acid residue as an N-Boc-aza¹-dipeptide. This approach has been validated by the synthesis of six N-Boc-aza¹-dipeptides and their subsequent introduction into analogues of the C-terminal peptide fragment of the human calcitonin gene-related peptide (hCGRP). By performing an aza-amino acid scan of such antagonist peptides, a set of aza-hCGRP analogues was synthesized to examine the relationship between turn secondary structure and biological activity.