1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 3: 93 percent / pyridine / 4 °C View Scheme

1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 3: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 4: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 5: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 6: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 7: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme

1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature View Scheme

1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 3: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature View Scheme

1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 3: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 4: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 5: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 6: 96 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 80 h / Ambient temperature View Scheme

1: DIBAL / toluene / 7 h / -78 °C 2: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 3: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 4: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 5: 94 percent / pyridine / 10 h / 4 °C 6: 67 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 7: 88 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 162 h / Ambient temperature View Scheme

oxalic acid in dichloromethane; water Ambient temperature; Yield given;