Solid phase synthesis of a ΨCH2NH pseudopeptide by ligation of a peptidyl aldehyde with a resin-bound amino peptide

Solid phase synthesis of Ψ[CH2NH] pseudopeptide 3 was accomplished by reductive amination of peptidyl aldehyde 1 with resin bound amino peptide 2. No epimerization took place during the aldehyde preparation or the reductive amination step. This convergent strategy should facilitate the synthesis of analogues of the neuropeptide PACAP.