bromine in tetrachloromethane; dichloromethane T=-78°C; 0.0833333 h;

bromine in dichloromethane T=-78°C; 0.166667 h;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.17 h / -78 °C 1.2: tetrahydrofuran; hexane / 0.17 h / -78 °C 2.1: 3.57 g / bromine / CH2Cl2 / 0.17 h / -78 °C View Scheme

1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2: 81 percent / DCC; DMAP / CH2Cl2 3: 6 percent / HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.33 h / -78 - 20 °C View Scheme

1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2: 81 percent / DCC; DMAP / CH2Cl2 3: 6 percent / HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.33 h / -78 - 20 °C 4: 72 percent / HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.33 h / -78 - 20 °C View Scheme

sodium tetrahydroborate in ethanol T=20°C; 3 h;

1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2: 84 percent / DMAP; pyridine / CH2Cl2 / 3 h / cooling View Scheme

1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2: 84 percent / DMAP; pyridine / CH2Cl2 / 3 h / cooling 3: 74 percent / HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.33 h / -78 - 20 °C View Scheme

1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2: 76 percent / DCC; DMAP / CH2Cl2 3: 94 percent / HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.33 h / -78 - 20 °C 4: 90 percent / DBU / tetrahydrofuran / 1 h / 20 °C View Scheme

1.1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 2.1: 78 percent / DCC; DMAP / CH2Cl2 3.1: HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.58 h / -78 - 20 °C 3.2: 83 percent / aq. HCl / tetrahydrofuran / 0.33 h 4.1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 5.1: 76 percent / K2CO3; MeOH / 20 °C View Scheme