Annulations via bifunctional reagents. Total syntheses of (±)-methyl cantabrenonate and (±)-methyl epoxycantabronate

Article abstract of DOI:10.1055/s-1992-34160

Total syntheses of the angularly fused triquinane sesquiterpenoids (±)-methyl cantabrenonate (10) and (±)-methyl epoxycantabronate (11) are described. The bicyclic enone, (RS)-5-methylbicyclo-[3.3.0]oct-1(8)-en-2-one (18), was readily obtained from 3-meth