Synthetic studies of furanosesquiterpenoid tetrahydrolinderazulenes. Total synthesis of (±)-echinofuran

Echinofuran () was isolated in 1992 and was reported to inhibit cell division of fertilized sea urchin eggs. The synthesis of was achieved by a Ring A→Ring AC→Ring ABC approach employing 3-methyl-4-(trimethylsilyl)furan () as a precursor. A Suzuki coupling reaction and a Lewis acid mediated Friedel-Crafts cyclization were the other key steps in the construction of the ring systems. In other preliminary model studies, two furan-containing 5,7,5-fused tricyclic molecules were also realized.