Abstract A synthesis of Z-Thr 1-D-Abu 2-Pro 3-MePhe 4-MeA 2 bu (γPht) 5-Phg 6-(A 2 bu= α, γ-diaminobutyric acid) is reported using the very efficient coupling agent BOP-Cl (N, N'-bis (3- oxo-2-oxazolidinyl) phosphinic chloride) for imino acid peptide bond formation. The total yield is 11% for the 5 coupling steps and one lactonization. The final step was a cyclization between residues 5 and 6, after (i) first t-Boc acidic deprotection with 85% HCOOH of the ...
