1.1: NaHMDS / tetrahydrofuran / 0.5 h / -78 °C 1.2: 92 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 20 h / -78 - 25 °C 2.1: 84 percent / aq. LiOH; aq. H2O2 / tetrahydrofuran / 0 - 20 °C 3.1: 0.34 g / trifluoroacetic acid / CH2Cl2 / 0 - 20 °C View Scheme

2: 93 percent / Zn powder, aq. 1N HCl, AcOH / 48 h / 0 °C 3: 1) 1N aq. LiOH, 2) Amberlite IR-120 / 1) THF, room temperature, 2) H2O, room temperature, 15 h View Scheme

1.1: NaHMDS / tetrahydrofuran / 0.5 h / -78 °C 1.2: hexamethylphosphoramide (HMPA) / tetrahydrofuran / 16 h / -78 °C 1.3: 92 percent / tetrahydrofuran / 4 h / 20 °C 2.1: 87 percent / CF3COOH / CH2Cl2 / 20 °C 3.1: 84 percent / 4-methylmorpholine (NMM); ClCOtBu / tetrahydrofuran / -12 °C 4.1: H2O2 / tetrahydrofuran; H2O / 1 h / 0 °C 4.2: 93 percent / tetrahydrofuran; H2O / 12 h / 20 °C View Scheme