With all the required fragments in hand we assembled the peptides on chlorotrityl chloride resin as was done for the total synthesis of Sanguinamide A (Scheme 5). The precursor pentapeptide sequence was assembled using regular Fmoc-SPPS and the dipeptide fragments were then coupled using COMU as the coupling reagents. For peptides SA-B3, SA-C3, and SA-D3, the Fmoc protected benzene amino acids 25-27 were coupled using PyBOP, followed by Fmoc removal and coupling of Boc-L-Ile-OH again using PyBOP. The N-terminal amine was always Boc protected so that treatment with TFA both liberated the N-terminus while simultaneously cleaving the peptide from the resin to provide the free C-terminal carboxylic acid. The peptides were cyclized in solution using PyBOP as coupling reagent under high dilution conditions (0.25 -0.5 mM) to avoid dimerization.