Results Synthesis of [Lactam3i4] Cs (4). The synthesis of the peptide portion of [lactam3s4] Cs (4) closely followed the strategy employed by Wengerl'" for synthesis of CsA (Figure 2). The tetra-and heptapeptide fragments 6 and 7 were assembled by the stepwise coupling strategy shown by the arrows (Figure 2) and coupled together to give the undecapeptide 5. The 6-membered lactam dipeptide moiety 8 was synthesized separately (vide infra) and ...
