A Concise Total Synthesis of Breitfussin A and B

The first total synthesis of breitfussin A and B is described. The approach features two palladium-catalyzed cross-couplings installing the indole and pyrrole onto the oxazole core and selective lithiation/iodination of a common indole-oxazole fragment providing 2,4-diiodinated or 2-iodinated oxazoles as potential precursors for breitfussin A and B, respectively. An unexpected acid promoted deiodination was utilized in the synthesis of breitfussin B. Comparison of the synthetic material with previously reported spectral data of isolated breitfussin A and B verified the structure of the breitfussin framework.