1: CH3SO2Cl, Et3N / CH2Cl2 / 0.67 h / 0 °C 2: 88 percent / tetrahydrofuran / Ambient temperature 4: 1.) CuCN 5: pyridinium p-toluenesulfonate (PPTS) / methanol; diethyl ether 6: CrO3, H+ 7: aq. HF / acetonitrile View Scheme

1: CH3SO2Cl, Et3N / CH2Cl2 / 0.67 h / 0 °C 2: 88 percent / tetrahydrofuran / Ambient temperature View Scheme

1: CH3SO2Cl, Et3N / CH2Cl2 / 0.67 h / 0 °C 2: 1.) CuCN / 2.) THF, from -78 deg C to 0 deg C, 1 h 3: pyridinium p-toluenesulfonate (PPTS) / methanol; diethyl ether 4: CrO3, H+ View Scheme

1: CH3SO2Cl, Et3N / CH2Cl2 / 0.67 h / 0 °C 2: 1.) CuCN / 2.) THF, from -78 deg C to 0 deg C, 1 h 3: pyridinium p-toluenesulfonate (PPTS) / methanol; diethyl ether 4: CrO3, H+ 6: Bu4NF View Scheme