Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra- cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

• Faruk H. Shaik and
• Gandhi K. Kar

Beilstein J. Org. Chem. 2009, 5, No. 47, doi:10.3762/bjoc.5.47

• extended for the synthesis of the tricyclic furoquinone, naphtho[1,2-b]furan-4,5-dione. Keywords: Fremy’s salt oxidation; furonaphthoquinone; furophenanthraquinone; Suzuki reaction; Introduction Chemistry of furoquinones [1][2][3][4][5][6][7][8], especially the tetra cyclic furoquinones isolated from

• is a furophenanthraquinone or a furonaphthoquinone as well as their di/tetra/hexahydro analog. We have not come across any synthesis of phenanthro[1,2-b]furo-10,11-dione (13) (the nuclear core structure of Tanshinone-I) though a number of syntheses of naturally occurring tetra cyclic furoquinone