Mitsunobu-Reaction-Based Total Solid-Phase Synthesis of Fanlizhicyclopeptide B

The first total synthesis of anti-inflammatory cyclic peptide fanlizhicyclopeptide B based on the Mitsunobu reaction is reported. The pre-made Fmoc-Tyr-OAllyl building block was coupled to the Wang resin via the Mitsunobu reaction catalyzed by triphenylphosphine and diethyl azodicarboxylate. After the remaining amino acids were assembled, macrocyclization was realized on solid support. Finally, the crude product was cleaved from resin and then purified by preparative reverse-phase high-performance liquid chromatography (RP-HPLC) to provide the pure target fanlizhicyclopeptide B.