silica gel in benzene 18 h; Ambient temperature;

1: sodium methoxide / methanol / 12 h / 25 °C 2: diisopropylethylamine / dimethylformamide / 24 h / 25 °C 3: 1.) sodium hydride / 1.) glyme, 0 deg C, 30 min, 2.) glyme, 25 deg C, 24 h 4: 1.5 h / Ambient temperature 5: 95 percent / silica gel / benzene / 18 h / Ambient temperature View Scheme

1: 1.) sodium hydride / 1.) glyme, 0 deg C, 30 min, 2.) glyme, 25 deg C, 24 h 2: 1.5 h / Ambient temperature 3: 95 percent / silica gel / benzene / 18 h / Ambient temperature View Scheme

1: diisopropylethylamine / dimethylformamide / 24 h / 25 °C 2: 1.) sodium hydride / 1.) glyme, 0 deg C, 30 min, 2.) glyme, 25 deg C, 24 h 3: 1.5 h / Ambient temperature 4: 95 percent / silica gel / benzene / 18 h / Ambient temperature View Scheme

1: 1.5 h / Ambient temperature 2: 95 percent / silica gel / benzene / 18 h / Ambient temperature View Scheme