potassium carbonate in N,N-dimethyl-formamide T=20 - 40°C; 2 h;

1: With hydrogen bromide; sodium nitrite in water T=0 - 5°C; 0.25 h; 2: With hydrogen bromide; copper(I) bromide in water T=20 - 75°C; 16 h;

1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.666667 h; 2: With boric acid trimethyl ester in tetrahydrofuran; hexane T=-78 - 20°C; 18 h; 3: With hydrogenchloride in tetrahydrofuran; hexane; water

boron tribromide in dichloromethane T=20°C;