1: 1.) NaCNBH3, 2.) n-BuLi / 1.) AcOH 2: 1.) n-BuLi 3: 4N HCl / tetrahydrofuran / Heating 4: MCPBA / CCl4 / Heating View Scheme

Multi-step reaction with 2 steps 1: n-BuLi / tetrahydrofuran / -78 °C2: 2.) (CF3CO)2O, Et3N, 4,4-dimethylaminopyridine / 1.) THF, 2.) CH2Cl2, 0 deg C  

Multi-step reaction with 2 steps 1: 1.) NaCNBH3, 2.) n-BuLi / 1.) AcOH2: 1.) n-BuLi