1: 77 percent / pyridinium chlorochromate (PCC) / CH2Cl2 / 0 °C 2: 1.) 2.3 M tert-butyllihium in pentane / 1.) THF, -78 deg C, 3 h, 2.) 10 min 3: 70percent aq. perchloric acid / dioxane / 0.5 h / Ambient temperature View Scheme

1: 71 percent / pyridinium chlorochromate (PCC) / CH2Cl2 / 0 °C 2: 1.) magnesium / 1.) THF, RT, 1 h, 2.) RT, 5 min 3: 1.) p-toluenesulfonic acid, 2.) 6 N aq. HCl / 1.) acetone, RT, 3 h, 2.) THF, reflux, 5 h View Scheme

1: 71 percent / pyridinium chlorochromate (PCC) / CH2Cl2 / 0 °C 2: 1.) magnesium / 1.) ether, 2.) RT, 15 min 3: triethylamine / CH2Cl2 / 0.08 h / 0 °C 4: triethylamine / CH2Cl2 / 0.33 h / Ambient temperature View Scheme

With  pyridinium chlorochromate in  dichloromethane T=0°C;   

Multi-step reaction with 2 steps 1: 71 percent / pyridinium chlorochromate (PCC) / CH2Cl2 / 0 °C2: 1.) magnesium / 1.) ether, 2.) RT, 15 min