1: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 4.5 h; Inert atmosphere; 2: With tri-isopropoxy-borane in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphere;

1.1: n-BuLi / hexane; tetrahydrofuran / 0.75 h / -78 °C 1.2: hexane; tetrahydrofuran / -78 - 20 °C 2.1: Br2; I2 / CH2Cl2 / 20 h / 20 °C 3.1: n-BuLi / diethyl ether / -78 - 20 °C 3.2: triisopropyl boronate / diethyl ether / 20 h / 20 °C 3.3: 65 percent / aq. HCl / diethyl ether / 1 h / 20 °C View Scheme

1.1: sodium hydride / tetrahydrofuran / 60 °C 1.2: 75.3 percent / tetrahydrofuran / Heating 2.1: magnesium; iodine / tetrahydrofuran / Heating 2.2: 31 percent / triethyl borate / tetrahydrofuran / 48 h / 20 °C View Scheme

1.1: 85 percent / KOH / tetrahydrofuran / 20 °C 2.1: ferric chloride; bromine / CHCl3 / 3 h / 20 °C 3.1: Mg; iodine / tetrahydrofuran 3.2: tetrahydrofuran / -78 - 20 °C 4.1: 4.3 g / aq. H2SO4 / cooling View Scheme

1.1: ferric chloride; bromine / CHCl3 / 3 h / 20 °C 2.1: Mg; iodine / tetrahydrofuran 2.2: tetrahydrofuran / -78 - 20 °C 3.1: 4.3 g / aq. H2SO4 / cooling View Scheme

hydrogenchloride in tetrahydrofuran; hexane

in toluene 11 h; Inert atmosphereReflux;