Synthesis of Microcin SF608

Abstract
The first total synthesis of aquatic peptide microcin SF608 is described. Coupling of l-Hpla with the dipeptide l-Phe-l-Choi followed by coupling with agmatine and a deprotection step gave microcin SF608. In addition, the levorotatory character of l-Hpla (5) was thoroughly established, and the conformational analysis of l-Choi containing peptides 1 and 8−10 was performed using NMR spectroscopy to examine the cis−trans isomer equilibrium of the l-Phe-l-Choi amide bond.