1: 85 percent / potassium t-butoxide / dimethylsulfoxide / 3 h / Ambient temperature 2: 14 percent Chromat. / 85percent phosphoric acid, 90percent formic acid / 3 h / 90 °C View Scheme

1: 85 percent / potassium t-butoxide / dimethylsulfoxide / 3 h / Ambient temperature 2: 1 percent Chromat. / 85percent phosphoric acid, 90percent formic acid / 3 h / 90 °C View Scheme