Structural Reassignment of a Marine Metabolite from a Binaphthalenetetrol to a Tetrabrominated Diphenyl Ether

The structure of a reported natural product isolate has been revised from (S)-2,2′-dimethoxy-[1,1′-binaphthalene]-5,5′,6,6′-tetraol to a known tetrabrominated diphenyl ether. After total synthesis of the reported binaphthalenetetrol was accomplished via a key reduction of a binaphtho-ortho-quinone, comparison of the physical properties and NMR spectroscopic data of the synthetic material indicated that the structure of the natural product isolate was incorrect. Evaluation of the authentic natural product suggested the structure is a tetrabrominated diphenyl ether, likely 3,5-dibromo-2-(3,5-dibromo-2-methoxyphenoxy)­phenol.