1: tert-butyl nitrite, potassium tert-butoxide / toluene; methanol / 3 h / 40 °C 2: 85 percent / NaOH / H2O; ethane-1,2-diol / 3 h / 155 - 160 °C View Scheme

1: tert-butyl nitrite, potassium tert-butoxide / toluene; methanol / 3 h / 40 °C 2: 88 percent / p-toluenesulfonic acid monohydrate / toluene / 1.5 h / Heating 3: 90 percent / toluene; ethanol / 0.02 h / Heating View Scheme

1: 70 percent / sodium bis(trimethylsilyl)amide / toluene; tetrahydrofuran / 2 h / 20 °C 2: 65 percent / tert-butyl nitrite, sodium bis(trimethylsilyl)amide / toluene; tetrahydrofuran / 1.5 h / 50 °C 3: p-TsOH, paraformaldehyde / acetic acid / 5 h / 100 - 105 °C 4: 40 percent / t-BuOK / 2 h / 20 °C View Scheme