1.1: 92 percent / PPh3; DEAD / tetrahydrofuran / 2 h / 20 °C 2.1: 77 percent / K2CO3; methanol / H2O / 2 h / 20 °C 3.1: 96 percent / triethylamine; 4-(dimethylamino)pyridine / dimethylformamide / 3 h / 20 °C 4.1: CuI / diethyl ether / 0.25 h / -30 °C 4.2: 92 percent / diethyl ether / 0.5 h / -40 °C 5.1: 97 percent / triethylamine / CH2Cl2 / 0.17 h / 0 °C 6.1: 88 percent / dimethylformamide; H2O / 20 h / 50 °C 7.1: 95 percent / triethylamine / CH2Cl2 / 6 h / 20 °C 8.1: tetrahydrofuran / 0 - 20 °C 9.1: 1.83 g / NaOH; H2O2 / H2O; ethanol; tetrahydrofuran / 1 h / 20 °C 10.1: 96 percent / Dess-Martin periodinane / CH2Cl2 / 0.25 h / 20 °C 11.1: 82 percent / tetrahydrofuran / 13 h / 65 °C 12.1: HCl / propan-2-ol / 3 h / 60 °C View Scheme