Patent ID: 7655809

Claim:
A method for the preparation of a compound comprising at least one linear series of five fused carbon rings, the method comprising the steps of: (a) providing an unsubstituted or substituted 1,4,5,8-anthradiquinone of the general formula I: wherein each R group is independently selected from the group consisting of hydrogen, an electron-withdrawing group, halogen, trialkylsilylalkynyl, and amine; (b) providing an unsubstituted or substituted acyclic, cyclic, or heterocyclic diene of the general formula IIa or IIb: wherein each R group is independently selected from the group consisting of hydrogen, an electron-withdrawing group, halogen, trialkylsilyl trialkylsilylalkynyl, alkoxy, aryloxy, and amine, and X is C, O, S, or N; (c) performing a double or stepwise cycloaddition reaction between the 1,4,5,8-anthradiquinone and the diene to generate a core structure comprising five fused carbon rings sequentially identified as rings A, B, C, D, and E in the compound of formula III: wherein each R group is as previously defined.