1.1: 98 percent / K2CO3 / dimethylformamide / 20 °C 2.1: 49 percent / sBuLi / tetrahydrofuran / -78 °C 3.1: 76 percent / IBX / toluene; dimethylsulfoxide / 20 °C 4.1: 63 percent / HCO2NH4 / Pd/C / acetone / 20 °C 5.1: PPh3; CCl4 / tetrahydrofuran / 20 °C 5.2: 43 percent / silica gel View Scheme