1: iPr2NEt / tetrahydrofuran / 12 h / Ambient temperature 2: 1.) n-BuLi, 2.) CuI / 1.) THF, -40 deg C, 20 min; 2.) THF, -78 deg C, 2 h 3: 10percent HCl / tetrahydrofuran; propan-2-ol / Ambient temperature 4: MnO2 / CH2Cl2 / Ambient temperature View Scheme