methanol; potassium carbonate T=20°C;

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

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 3.1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 4.1: 78 percent / DCC; DMAP / CH2Cl2 5.1: HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.58 h / -78 - 20 °C 5.2: 83 percent / aq. HCl / tetrahydrofuran / 0.33 h 6.1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 7.1: 76 percent / K2CO3; MeOH / 20 °C View Scheme

1.1: 3.57 g / bromine / CH2Cl2 / 0.17 h / -78 °C 2.1: 76 percent / NaBH4 / ethanol / 3 h / 20 °C 3.1: 78 percent / DCC; DMAP / CH2Cl2 4.1: HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.58 h / -78 - 20 °C 4.2: 83 percent / aq. HCl / tetrahydrofuran / 0.33 h 5.1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 6.1: 76 percent / K2CO3; MeOH / 20 °C View Scheme

1.1: 78 percent / DCC; DMAP / CH2Cl2 2.1: HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.58 h / -78 - 20 °C 2.2: 83 percent / aq. HCl / tetrahydrofuran / 0.33 h 3.1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 4.1: 76 percent / K2CO3; MeOH / 20 °C View Scheme

1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 2: 76 percent / K2CO3; MeOH / 20 °C View Scheme

1.1: HMPA; tert-butyldimethylsilyl chloride; LHMDS / tetrahydrofuran / 1.58 h / -78 - 20 °C 1.2: 83 percent / aq. HCl / tetrahydrofuran / 0.33 h 2.1: 91 percent / DBU / tetrahydrofuran / 1 h / 20 °C 3.1: 76 percent / K2CO3; MeOH / 20 °C View Scheme