Dehydration of erythritol in high-temperature carbonated water

Intramolecular dehydration of erythritol to 1,4-anhydroerythritol proceeded in liquid water at 573 K. The initial formation rate and final yield of 1,4-anhydroerythritol were 0.50 mmol h(-1) and 71%, respectively. Addition of carbon dioxide up to the pressure of 17.7 and 24.8 MPa to water solvent at 573 K, the initial product formation rates dramatically increased to 1.45 and 2.10 mmol h(-1), respectively; however, the final yields were almost the same as 73 and 71%, respectively. These results showed that the protons derived from carbonic acid catalyzed the intramolecular dehydration and the concentration of proton increased with an increase in the carbon dioxide pressure introduced.