1: 2,3-dibromofuran With n-butyllithium in diethyl ether; hexane T=-70°C; 0.833333 h; Inert atmosphere; 2: N,N-dimethyl acetamide in diethyl ether; hexane T=-70 - -10°C; 1 h; 3: With tri-isopropoxy-borane in diethyl ether; hexane T=-70 - 0°C;