1: BF3*Et2O / tetrahydrofuran / 64 h / Heating 2: 81 percent / DDQ / toluene / 18 h / Heating View Scheme

1: BF3*OEt2 / dioxane 2: 56 percent / DDQ / toluene / Heating View Scheme

1.1: 35 percent / AgNO3; ammonium persulfate / acetonitrile; H2O / 6 h / 65 - 70 °C 2.1: m-chloroperbenzoic acid / CH2Cl2 / 16 h / 20 °C 3.1: sodium dithionite / diethyl ether; H2O / 0.5 h / 20 °C 3.2: 1.26 g / acetic acid; sulfuric acid / H2O / 6 h / 20 °C 4.1: 90 percent / K2CO3 / acetone / 3 h / Heating 5.1: 95 percent / N-bromosuccinimide / CH2Cl2 / 0.17 h / 20 °C 6.1: pyridine / 16 h / 20 °C 7.1: 73 percent / KOtBu / tetrahydrofuran / 6 h / 20 °C 8.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 8.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 9.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme

1: BF3*Et2O / tetrahydrofuran / 64 h / Heating 2: 81 percent / DDQ / toluene / 18 h / Heating View Scheme

1.1: BF3*Et2O / CH2Cl2 / 1.5 h / -78 °C 1.2: 48 percent / Ag2O / diethyl ether / 5 h / 20 °C 2.1: 79 percent / pyridine / 0.17 h / 20 °C View Scheme

1.1: sodium dithionite / diethyl ether; H2O / 0.5 h / 20 °C 1.2: 1.26 g / acetic acid; sulfuric acid / H2O / 6 h / 20 °C 2.1: 90 percent / K2CO3 / acetone / 3 h / Heating 3.1: 95 percent / N-bromosuccinimide / CH2Cl2 / 0.17 h / 20 °C 4.1: pyridine / 16 h / 20 °C 5.1: 73 percent / KOtBu / tetrahydrofuran / 6 h / 20 °C 6.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 6.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 7.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme

1.1: 95 percent / N-bromosuccinimide / CH2Cl2 / 0.17 h / 20 °C 2.1: pyridine / 16 h / 20 °C 3.1: 73 percent / KOtBu / tetrahydrofuran / 6 h / 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 4.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 5.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 2.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme

1.1: 90 percent / K2CO3 / acetone / 3 h / Heating 2.1: 95 percent / N-bromosuccinimide / CH2Cl2 / 0.17 h / 20 °C 3.1: pyridine / 16 h / 20 °C 4.1: 73 percent / KOtBu / tetrahydrofuran / 6 h / 20 °C 5.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 5.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 6.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme

1.1: pyridine / 16 h / 20 °C 2.1: 73 percent / KOtBu / tetrahydrofuran / 6 h / 20 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 3.2: 57 percent / tetrahydrofuran; hexane / 2 h / -78 °C 4.1: 77 percent / AlCl3 / CH2Cl2 / 4 h / 20 °C View Scheme