Synthesis, crystal structure and molecular conformation of Nα‐Boc‐l‐leucyl‐(Z)‐β‐(3‐pyridyl)‐α,β‐ dehydroalanyl‐l‐leucine methyl ester*

Abstract:  A protected tridehydropeptide containing (Z)-β-(3-pyridyl)-α,β-dehydroalanine (ΔZ3Pal) residue, Boc-Leu-ΔZ3Pal-Leu-OMe (1), was synthesized via Erlenmeyer azlactone method. X-ray crystallographic analysis revealed that the peptide 1 adopts an extended conformation, which is similar to that of a ΔZPhe analog, Boc-Leu-ΔZPhe-Leu-OMe (2).