1: 4,4-bis(2-ethylhexyl)-4H-cyclopenta(2,1-b:3,4-b’)-dithiophene With n-butyllithium in tetrahydrofuran; hexanes T=-78 - 20°C; 4 h; 2: trimethylstannyl chloride in tetrahydrofuran; hexanes T=-78 - 20°C;