phosphoric acid 3 h; Ambient temperature;

phosphoric acid 3 h; Ambient temperaturevariation of acids, reaction times and temperatures; Product distributionMechanism;

1: 92 percent / pyridine / Ambient temperature 2: 1.) BuLi, diisopropylamine / 1.) THF, hexane, -78 deg C, 1 h, 2.) -78 deg C, 2 h 3: 83 percent / trifluoroacetic acid (TFA) / Ambient temperature 4: 92 percent / Li, NH3 / tetrahydrofuran 5: 87 percent / KOH / H2O / 24 h / Heating View Scheme