Total Synthesis of the Tetrasubstituted Furan Fatty Acid Metabolite CeDFP via Au-Catalyzed Intermolecular Alkyne Hydroarylation.

The first total synthesis of the tetrasubstituted furan fatty acid (FFA) metabolite 5-[(1 E)-2-carboxyethenyl]-3,4-dimethyl-2-furanpentanoic acid (CeDFP) is reported. CeDFP is a FFA metabolite isolated from shark livers and is related to the known FFA metabolites CMPF and CMPentylF. Key elements of the synthetic route to CeDFP include an iodine-promoted 5- endo- dig cyclization of a 1,2-alkyne diol, a methyllithium-mediated insertion of the C3-methyl group, and a Au(I)-catalyzed intermolecular hydroarylation to introduce the unsaturated ester.