1: N-iodosuccinimide / 1 h / -20 °C 2: SnCl4 / 1,2-dichloro-ethane / -20 deg C -> 23 deg C 3: H2 / 10 percent Pd/C / ethanol / 3 h 4: CH3ONa / methanol / 5 h / 23 °C View Scheme

1: 94 percent / I2 / CH2Cl2 / 2 h / -30 °C 2: NaOMe / methanol / 18 h / 20 °C View Scheme

1: OsO4, N-methylmorpholine N-oxide / tetrahydrofuran; 2-methyl-propan-2-ol; H2O / 4 h / 20 °C 2: Et3N / CH2Cl2 / 22 h / 20 °C 3: 65 percent / trimethylsilyl triflate / 1,2-dichloro-ethane / 3 h / Heating 4: 42 percent / NaOMe / methanol / 20 h / 20 °C View Scheme

1: N-iodosuccinimide / tetrahydrofuran / 2 h / -15 °C 2: DBU / CH2Cl2 / 1 h / 0 °C 3: 82 percent / potassium t-butoxide / tetrahydrofuran / 1 h / 0 °C View Scheme

1: OsO4, N-methylmorpholine N-oxide / tetrahydrofuran; 2-methyl-propan-2-ol; H2O / 4 h / 20 °C 2: Et3N / CH2Cl2 / 22 h / 20 °C 3: 65 percent / trimethylsilyl triflate / 1,2-dichloro-ethane / 3 h / Heating 4: 16 percent / NaOMe / methanol / 20 h / 20 °C View Scheme