Synthesis of the Natural Product Iotrochamide B

Iotrochamide B is the first cinnamoyl amino acid reported from the marine sponge Iotrochota sp. The total synthesis of the marine indole alkaloid iotrochamide B was achieved by condensation of 6-bromo-L-tryptophan (3) and (Z)-2-methoxy-3-phenylacrylic acid (6). The key step was the synthesis of 6-bromo-L-tryptophan ((S)-3) from racemic N-acetyltryptophan by optical resolution using (S)-(-)-1-phenylethylamine. This work provides an efficient method for future synthesis of iotrochamide B derivatives.