sodium hydroxide in methanol 3 h; Ambient temperature;

1: 85percent HClO4 / toluene / 1 h / Ambient temperature 2: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 3: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 85 percent / SO3 pyridine complex / triethylamine; dimethylsulfoxide / 3 h / Ambient temperature 2: 85 percent / triethylorthoformate, p-toluenesulfonic acid hydrate / 3 h / 40 °C 3: 85 percent / NaH / dimethylsulfoxide; toluene / 12 h / 80 °C / sonification 4: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 5: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 6: 85percent HClO4 / toluene / 1 h / Ambient temperature 7: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 8: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 2: 85percent HClO4 / toluene / 1 h / Ambient temperature 3: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 4: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 85 percent / triethylorthoformate, p-toluenesulfonic acid hydrate / 3 h / 40 °C 2: 85 percent / NaH / dimethylsulfoxide; toluene / 12 h / 80 °C / sonification 3: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 4: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 5: 85percent HClO4 / toluene / 1 h / Ambient temperature 6: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 7: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 92 percent / HCl / acetone; H2O 2: boron trifluoride diethyl ether / methanol / 1 h / Ambient temperature 3: 87 percent / Li, ethylamine / tetrahydrofuran / 0.5 h / -35 - -30 °C 4: 85 percent / SO3 pyridine complex / triethylamine; dimethylsulfoxide / 3 h / Ambient temperature 5: 85 percent / triethylorthoformate, p-toluenesulfonic acid hydrate / 3 h / 40 °C 6: 85 percent / NaH / dimethylsulfoxide; toluene / 12 h / 80 °C / sonification 7: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 8: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 9: 85percent HClO4 / toluene / 1 h / Ambient temperature 10: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 11: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 87 percent / Li, ethylamine / tetrahydrofuran / 0.5 h / -35 - -30 °C 2: 85 percent / SO3 pyridine complex / triethylamine; dimethylsulfoxide / 3 h / Ambient temperature 3: 85 percent / triethylorthoformate, p-toluenesulfonic acid hydrate / 3 h / 40 °C 4: 85 percent / NaH / dimethylsulfoxide; toluene / 12 h / 80 °C / sonification 5: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 6: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 7: 85percent HClO4 / toluene / 1 h / Ambient temperature 8: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 9: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 2: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 3: 85percent HClO4 / toluene / 1 h / Ambient temperature 4: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 5: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 2: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme

1: 85 percent / NaH / dimethylsulfoxide; toluene / 12 h / 80 °C / sonification 2: p-toluenesulfonic acid hydrate / acetone / 12 h / Ambient temperature 3: 85 percent / Li, ethylenediamine / tetrahydrofuran / 2 h / 25 °C / continuous flow of ethyne 4: 85percent HClO4 / toluene / 1 h / Ambient temperature 5: tert. butyl chromate / CCl4; acetic acid; acetic anhydride / 5 h / Heating 6: 62 percent / NaOH / methanol / 3 h / Ambient temperature View Scheme