1: 97 percent / PPh3, imidazole, I2 / toluene / 1.) 60 deg C, 10 min, 2.) reflux, 3.75 h 2: 98 percent / DBU / xylene / 16.5 h / Heating 3: CAN / acetonitrile; H2O / 0.28 h / 0 °C View Scheme

1: 97 percent / PPh3, imidazole, I2 / toluene / 1.) 60 deg C, 10 min, 2.) reflux, 3.75 h 2: 98 percent / DBU / xylene / 16.5 h / Heating 3: CAN / acetonitrile; H2O / 0.28 h / 0 °C 4: DMAP, pyridine / 22 h 5: 93 percent / NaBH4 / methanol / 2.5 h View Scheme

1: 97 percent / PPh3, imidazole, I2 / toluene / 1.) 60 deg C, 10 min, 2.) reflux, 3.75 h 2: 98 percent / DBU / xylene / 16.5 h / Heating 3: CAN / acetonitrile; H2O / 0.28 h / 0 °C 4: DMAP, pyridine / 22 h View Scheme