Total Synthesis of the Chlorinated Marine Natural Product Dysamide B

Two approaches to the synthesis of (2S,4S)-5,5-dichloroleucine are compared, and the parent amino acid was used in the first total synthesis of the polychlorinated marine natural product, dysamide B. A key step was the lead tetraacetate-mediated decarboxylation of an α,α-dichloro acid in the presence of 1,4-cyclohexadiene to generate the dichloromethyl group.