1.1: 98 percent / imidazole / dimethylformamide / 24 h / 30 °C 2.1: O3 / CH2Cl2 / -78 °C 2.2: 90 percent / PPh3 / 4 h / 20 °C 3.1: 90 percent / NaH2PO4; KMnO4 / H2O; 2-methyl-propan-2-ol / 0.5 h / 20 °C 4.1: 93 percent / BF3*Et2O / acetonitrile / 2 h / 0 °C View Scheme

1: 90 percent / NaH2PO4; KMnO4 / H2O; 2-methyl-propan-2-ol / 0.5 h / 20 °C 2: 93 percent / BF3*Et2O / acetonitrile / 2 h / 0 °C View Scheme

1.1: O3 / CH2Cl2 / -78 °C 1.2: 90 percent / PPh3 / 4 h / 20 °C 2.1: 90 percent / NaH2PO4; KMnO4 / H2O; 2-methyl-propan-2-ol / 0.5 h / 20 °C 3.1: 93 percent / BF3*Et2O / acetonitrile / 2 h / 0 °C View Scheme

1.1: diethyl ether / 5 h / -100 - 23 °C 1.2: NaOH; H2O2 / H2O / 1 h / Heating 2.1: 95 percent / imidazole / dimethylformamide / 24 h / 30 °C 3.1: BH3*SMe2 / tetrahydrofuran / 2.5 h / -78 - 0 °C 3.2: 85 percent / NaOH; H2O2 / H2O / 3.5 h / 20 °C 4.1: 95 percent / Dess-Martin reagent / CH2Cl2 / 2 h / 20 °C 5.1: diethyl ether / 5 h / -100 - 23 °C 5.2: NaOH; H2O2 / H2O / 1 h / Heating 6.1: 98 percent / imidazole / dimethylformamide / 24 h / 30 °C 7.1: O3 / CH2Cl2 / -78 °C 7.2: 90 percent / PPh3 / 4 h / 20 °C 8.1: 90 percent / NaH2PO4; KMnO4 / H2O; 2-methyl-propan-2-ol / 0.5 h / 20 °C 9.1: 93 percent / BF3*Et2O / acetonitrile / 2 h / 0 °C View Scheme

1.1: 88 percent / (COCl)2 / dimethylsulfoxide; CH2Cl2 / 0.5 h / -78 - 0 °C 2.1: diethyl ether / 5 h / -100 - 23 °C 2.2: NaOH; H2O2 / H2O / 1 h / Heating 3.1: 95 percent / imidazole / dimethylformamide / 24 h / 30 °C 4.1: BH3*SMe2 / tetrahydrofuran / 2.5 h / -78 - 0 °C 4.2: 85 percent / NaOH; H2O2 / H2O / 3.5 h / 20 °C 5.1: 95 percent / Dess-Martin reagent / CH2Cl2 / 2 h / 20 °C 6.1: diethyl ether / 5 h / -100 - 23 °C 6.2: NaOH; H2O2 / H2O / 1 h / Heating 7.1: 98 percent / imidazole / dimethylformamide / 24 h / 30 °C 8.1: O3 / CH2Cl2 / -78 °C 8.2: 90 percent / PPh3 / 4 h / 20 °C 9.1: 90 percent / NaH2PO4; KMnO4 / H2O; 2-methyl-propan-2-ol / 0.5 h / 20 °C 10.1: 93 percent / BF3*Et2O / acetonitrile / 2 h / 0 °C View Scheme