Total synthesis and stereochemical reassignment of tasiamide B

The first total synthesis of tasiamide B, an octapeptide bearing 4‐amino‐3‐hydroxy‐5‐phenylpentanoic acid unit isolated from the marine cyanobacteria Symploca sp. is described. A simple and efficient way was found to avoid the pyroglutamylation of N^α‐Me‐Gln and led to a reassignment of the N^α‐Me‐L ‐Phe of tasiamide B to be N^α‐Me‐D ‐Phe, which was also supported by 1D and 2D NMR. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.