A conceptually new method for synthesis of tetrasubstituted thiophenes in two steps from trans-2-aroyl-3-aryl-cyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol has been developed. It involves AlCl3-mediated [3+3] annulation of the cyclopropane-derived 1,3-zwitterionic intermediates with in situ more...