Synthesis of antiaromatic tetrabenzodithiaamethyrin

Bicyclo[2.2.2]octadiene(BCOD)-fused dithiaamethyrin 4 was synthesized via a “3+3” condensation method. Thermal conversion of the BCOD moieties afforded tetrabenzodithiaamethyrin 5. The highly planar structures of 4 and 5 were confirmed by X-ray diffraction studies. The 1 H NMR, absorption and MCD spectra, together with TD-DFT calculations revealed that both BCOD-fused and [Formula: see text]-extended dithiaamethyrins have a 24[Formula: see text] antiaromatic character.