Chloroacetic acid was used as catalyst for the hydration of alpha-pinene using water as hydroxyl donor, which is soluble in aqueous and organic solvents. The highest selectivity was 95.5 with a conversion of 10%, whereas the higher conversion was 99% with selectivity of 70% after 4 h of reaction at 70 degrees C. Organo-chlorinated compounds were not found in products as in the case of the use of HCl as catalyst, which indicates that the intermediate carbocation formed after alkene protonation is not susceptible to react with the chloroacetic anion. (c) 2005 Elsevier B.V. All rights reserved.