in acetic anhydride 1 h; Ambient temperature;

1: 85 percent / acetic anhydride / 1 h / Ambient temperature 2: Na2CO3, tetrabutylammonium bromide / H2O; CH2Cl2 / 2 h / Ambient temperature 3: 39 percent / p-toluenesulfonic acid / methanol / 3 h / Heating View Scheme

Multi-step reaction with 2 steps 1: 85 percent / acetic anhydride / 1 h / Ambient temperature2: Na2CO3, tetrabutylammonium bromide / H2O; CH2Cl2 / 2 h / Ambient temperature  

Multi-step reaction with 3 steps 1: 85 percent / acetic anhydride / 1 h / Ambient temperature2: Na2CO3, tetrabutylammonium bromide / H2O; CH2Cl2 / 2 h / Ambient temperature3: 43 percent / p-toluenesulfonic acid / 3 h / Heating  

Multi-step reaction with 3 steps 1: 85 percent / acetic anhydride / 1 h / Ambient temperature2: Na2CO3, tetrabutylammonium bromide / H2O; CH2Cl2 / 2 h / Ambient temperature3: 9 percent / p-toluenesulfonic acid / 3 h / Heating