1: 89 percent / BuLi / tetrahydrofuran / 0.25 h / 0 °C 2: 59 percent / AgOTf / CH2Cl2 / 17 h / Ambient temperature View Scheme

Multi-step reaction with 3 steps 1: 75 percent / LAH / tetrahydrofuran / 1 h / Heating2: 80 percent / CrO3-pyridine / CH2Cl2 / 0.25 h / Ambient temperature3: 60 percent / HCl gas / CHCl3 / 4 h / Ambient temperature