Synthesis of the core framework of the proposed structure of sargafuran

Synthesis of 2-homoprenyl-1-methyl-3-(5-methylfuran-2-yl)cyclopenta-2,4-dien-1-ol, the core framework of the proposed structure of the brown alga derived natural product sargafuran, was achieved in six steps from the commercially available 5-methylfurfural via the Piancatelli rearrangement of furylcarbinol. The concise synthetic route to the 1,2,3-trisubstituted cyclopentadienol is established. However, the 1H and 13C NMR spectral data of the synthetic analog of sargafuran suggest that the originally proposed structure of sargafuran must be incorrect. In addition, the structure of the natural sargafuran is also discussed.