1: With n-butyllithium in tetrahydrofuran; diethyl ether; hexane T=-98°C; 0.0833333 h; 2: With boric acid trimethyl ester in tetrahydrofuran; diethyl ether; hexane T=-98 - 20°C; 12 h; 3: With hydrogenchloride in tetrahydrofuran; diethyl ether; hexane T=20°C;

1.1: 89 percent / Br2 / CCl4 / 24 h / 20 °C 2.1: 76 percent / K2CO3 / acetone / 24 h / Heating 3.1: n-BuLi / tetrahydrofuran; hexane; diethyl ether / 0.08 h / -98 °C 3.2: B(OMe)3 / tetrahydrofuran; hexane; diethyl ether / 12 h / -98 - 20 °C 3.3: 65 percent / aq. HCl / tetrahydrofuran; hexane; diethyl ether / 20 °C View Scheme

1.1: 76 percent / K2CO3 / acetone / 24 h / Heating 2.1: n-BuLi / tetrahydrofuran; hexane; diethyl ether / 0.08 h / -98 °C 2.2: B(OMe)3 / tetrahydrofuran; hexane; diethyl ether / 12 h / -98 - 20 °C 2.3: 65 percent / aq. HCl / tetrahydrofuran; hexane; diethyl ether / 20 °C View Scheme