acetic acid in dichloromethane; water

pyridine; chromium(VI) oxide; Celite in dichloromethane 0.333333 h;

1: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 30 min, 2.) THF, hexane, a) from -50 deg C to RT, b) RT, 3.5 h 2: 92 percent / p-TsOH*H2O / benzene / 6 h / Heating 3: 60 percent / borane-tetrahydrofuran complex, 3 N aq. NaOH, 30percent aq. H2O2 / tetrahydrofuran / 0.5 h / Ambient temperature 4: 0.85 g / pyridine, chromium trioxide, Celite / CH2Cl2 / 0.33 h View Scheme

1: 92 percent / p-TsOH*H2O / benzene / 6 h / Heating 2: 60 percent / borane-tetrahydrofuran complex, 3 N aq. NaOH, 30percent aq. H2O2 / tetrahydrofuran / 0.5 h / Ambient temperature 3: 0.85 g / pyridine, chromium trioxide, Celite / CH2Cl2 / 0.33 h View Scheme

1: 60 percent / borane-tetrahydrofuran complex, 3 N aq. NaOH, 30percent aq. H2O2 / tetrahydrofuran / 0.5 h / Ambient temperature 2: 0.85 g / pyridine, chromium trioxide, Celite / CH2Cl2 / 0.33 h View Scheme