[reaction: see text] A conceptually new approach to the tetracyclic core of the anthracyclineantibiotics is reported. With use of this approach, the 7,8,9,10-tetrahydronaphthacene-5,12-dione skeleton has been synthesized in three steps, from commercially available reagents, in yields of up to 85%.
New cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs) based on tetracene have been prepared by a palladium-catalyzed cyclopentannulation reaction. The new compounds have low-energy lowest unoccupied molecular orbitals (LUMOs) and relatively small band gaps. The photooxidative stability was intermediate to previously prepared CP-PAHs based on anthracene and pentacene as found in traditional