2: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 3: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 4: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 5: 1) CuCN / 1) ether, -78 to -40 deg C, 2) ether, -78 to -20 deg C, then 2 h 6: 64 percent / MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 7: 88 percent / p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme

2: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 3: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 4: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 5: 1) CuCN / 1) ether, -78 to -40 deg C, 2) ether, -78 to -20 deg C, then 2 h 6: 58 percent / MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 7: 90 percent / p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme

2: 88.5 percent / p-toluenesulfonic acid / CH2Cl2 / Ambient temperature 3: tetrabutylammonium fluoride / tetrahydrofuran / 1 h / Ambient temperature 4: 94 percent / pyridine / CHCl3 / a) 0 deg C, 6 h, b) r.t., overnight 5: 76 percent / LiAlH4 / diethyl ether / 48 h / Heating 6: MeI, CaCO3 / acetonitrile; H2O / 24 h / 35 °C 7: p-toluenesulfonic acid / ethanol / 2 h / 55 °C View Scheme