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 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: 96 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 80 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: 94 percent / pyridine / 10 h / 4 °C 7: 67 percent / SeO2 / 2-methyl-propan-2-ol; benzene / Heating 8: 88 percent / acetic acid (glacial) / tetrahydrofuran; H2O / 162 h / Ambient temperature View Scheme

1: 74 percent / n-BuLi / tetrahydrofuran / 1.) -78 deg C, 90 min, 2.) -78 deg C, 15 min 2: 90 percent / cupric sulfate / acetone View Scheme

1: n-BuLi / 1.) -70 deg C., ether, hexane; 2.) room temp 2: 2.) KF*2H2O / 1) Irradiation 2) DMSO, 9 hr. room temp View Scheme

Yield given. Multistep reaction;

2: silica gel, FeCl3-SiO2 / 4 h / 20 °C View Scheme