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.