1: allyltributylstannane With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With copper(l) iodide in tetrahydrofuran; hexane T=-78 - -30°C; 0.75 h; 3: but-2-ynoic acid 9H-fluoren-9-ylmethyl ester in tetrahydrofuran; hexane T=-78°C; 0.25 h;