1: 2,6-lutidine / CH2Cl2 / 0 °C 2: 56 percent / tert-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / 1.) -78 deg C, 10 min, 2.) -78 deg C, 30 min 3: NCS, aq. AgNO3, 2,4,6-collidine / acetonitrile / 0.02 h / 0 °C 4: 65 percent / NaBH(OAc)3 / acetonitrile; acetic acid / 5 h / 0 °C 5: 82 percent / TBAF / tetrahydrofuran / Ambient temperature 6: 87 percent / MnO2 / CH2Cl2 / 3 h / Ambient temperature View Scheme