Total synthesis of didmolamides A and B

The first total synthesis of didmolamides A (1) and B (2) has been accomplished by the solid phase assembly of thiazole-containing amino acids and commercially available Fmoc-protected amino acids. The synthesis of didmolamide B was also achieved in high yield using solution phase peptide synthesis. The thiazole-containing amino acid composing 1 and 2 was synthesized by a MnO2 oxidation of a thiazoline, prepared from an Ala-Cys dipeptide using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate. The final macrolactamization was accomplished efficiently by PyBOP and DMAP in solution.