1: 26.2 percent / Et3N, Ac2O / 22 h / 70 °C / investigation of the degradation reaction in the acetic anhydride-base system; mechanism is proposed 2: 65.3 percent / Et3N, Ac2O / 30 h / 70 °C View Scheme

acetic anhydride; triethylamine T=70°C; 22 h;

acetic anhydride; triethylamine 24 h; Ambient temperature;

1: 26.2 percent / Et3N, Ac2O / 22 h / 70 °C / investigation of the degradation reaction in the acetic anhydride-base system; mechanism is proposed 2: 4.5 percent / Et3N, Ac2O / 30 h / 70 °C View Scheme

acetic anhydride; triethylamine T=70°C; 22 h;

1: sodium hydrogencarbonate / N,N-dimethyl-formamide / 16 h / 20 °C 2: trimethylsilylazide; tin(IV) chloride / dichloromethane / 24 h / 0 - 20 °C 3: titanium tetrachloride / dichloromethane / 48.17 h / -15 - 0 °C 4: lithium iodide / ethyl acetate / 16 h / |Reflux 5: borane-THF / tetrahydrofuran / 0 - 20 °C 6: pyridine / 4 h / 20 °C View Scheme