1: tetrahydrofuran; hexamethylphosphoric acid triamide / 18 h / Ambient temperature 2: n-BuN(1+)*F(1-) / tetrahydrofuran / 0.5 h / Ambient temperature 3: 80 percent / AIBN / benzene / 18 h / Heating 4: tetrahydrofuran / 0 deg C, 1-2 h then R.T., 1-2 h 5: Na/Hg, Na2HPO4 / tetrahydrofuran; methanol / 20 h / Ambient temperature 6: 67 percent / TsOH / dioxane; H2O / 1 h / 80 °C View Scheme

1: 92 percent / dimethylformamide / 3 h / Heating 2: 81 percent / butyllithium / tetrahydrofuran; pentane / Ambient temperature 3: 74 percent / Li, NH3, ethanol / tetrahydrofuran / 0.5 h / -78 °C 4: 87 percent / glacial AcOH / 6 h / Ambient temperature 5: 92 percent / K2Os2(OH)4, (DHQD)2PHAL, K2CO3, potassium ferricyanate, CH3SO2NH2 / H2O; 2-methyl-propan-2-ol / 96 h / Ambient temperature 6: 1) CH3SO2Cl, pyridine, 2) K2CO3 / 1) CH2Cl2, RT, 2) aq. CH3OH, RT, 18 h View Scheme

1.1: LDA / tetrahydrofuran / 0.67 h / -78 - 0 °C 1.2: 93 percent / tetrahydrofuran / -78 - 0 °C 2.1: 68 percent / aq. p-TsOH / dioxane / 5 h / Heating View Scheme