acetic acid in tetrahydrofuran; water 168 h; Ambient temperature;

trifluoroacetic acid T=0°C; 3 h;

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: 1.) n-BuLi, 2.) / 1.) THF, -78 deg C, 2.) -78 deg C 2: DIBAL / toluene / 7 h / -78 °C 3: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 4: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 5: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 6: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 7: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 8: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme

1: 85 percent / TsOH*H2O / benzene / 43 h / Heating; azeotropic removal of water 2: 1.) n-BuLi, 2.) / 1.) THF, -78 deg C, 2.) -78 deg C 3: DIBAL / toluene / 7 h / -78 °C 4: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 5: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 6: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 7: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 8: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 9: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme

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

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

1: 82 percent / fumaric acid / benzene / 68 h / Heating; azeotropic removal of water 2: DIBAL / toluene / 7 h / -78 °C 3: oxalic acid / CH2Cl2; H2O / 3.5 h / Ambient temperature 4: 78 percent / imidazole / dimethylformamide / 65 h / Ambient temperature 5: 1.) OsO4, 2.) aq. NaHSO3 / 1.) a) pyridine, 0-5 deg C, b) RT, 5 h, 2.) pyridine, RT, 3 h 6: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 7: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 8: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme

1: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 2: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme

1: 53 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 2: 61 percent / CrO3, H2SO4 / acetone / 1 h / -10 °C 3: 73.8 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 168 h / Ambient temperature View Scheme