Total Synthesis of (±)-Scirpene

The racemate of scirpene, 12,13-epoxytrichothec-9-ene, was synthesized from 3-methoxyacetophenone. The key step in the synthesis is the palladium-mediated ring expansion reaction of the vinylcyclobutanol derivative, prepared via the oxidative ring expansion reaction of the cyclopropylidene. (3 S *)-3-[(1 S *,6 S *)-3-Methyl-9-oxabicyclo[4.3.0]non-2-en-6-yl]-3-methyl-2-methylenecyclo-pentan-1-one formed from the reaction was converted into (±)-scirpene through the ring opening of tetrahydrofuran part, followed by cyclization for construction of the desired skeleton.