1: 78 percent / silica gel / pentane; diethyl ether 2: 79 percent / tetrahydrofuran / -78 - 0 °C 3: 85 percent / sodium hydride / tetrahydrofuran / 3 h / Heating View Scheme

1: 78 percent / silica gel / pentane; diethyl ether 2: 59 percent / toluene; tetrahydrofuran / -78 - 0 °C View Scheme