1: alpha-Terthiophene With n-butyllithium in tetrahydrofuran; hexane T=-40°C; 1 h; 2: With tributoxyborane in tetrahydrofuran; hexane T=-90°C; 1 h; 3: 3-hydroxy-2,2-dimethylpropanol in tetrahydrofuran; hexane T=20°C; 0.25 h; Further stages.;