1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: With tri-isopropoxy-borane in tetrahydrofuran; hexane T=-78 - 25°C; 1 h; 3: With hydrogenchloride in tetrahydrofuran; hexane; water T=25°C; 0.5 h;