In the superacid HSO₃F, diarylacetylenes bearing one electron-withdrawing group (NO₂, CN, COMe, CO₂Me) in each arene ring form stable ions, protonated at these groups. Oxidation of such diarylacetylenes in the HSO₃F/PbO₂ system at -75 to -50°C over 2-2.5 h, followed by quenching of the reaction mixture with hydrochloric (or hydrobromic) acid at -60 to 25°C, resulted in the formation of (E,E)-1,4-dichloro (or dibromo)-1,2,3,4-tetraarylbuta-1,3-dienes. These butadienes spontaneously undergo electrocyclic transformation into polysubstituted naphthalenes at room temperature.