Evaluation of Some of the Factors Involved in the Selective Hydrolysis of Aromatic Ester Protecting Groups by α-Chymotrypsin

Abstract

Studies have been carried out which delineate some of the factors involved in the exploitation of α-chymotrypsin as a catalyst for the specific hydrolysis of selected aromatic ester protecting groups under mild conditions with a specificity not achievable by non-enzymic reagents. The reactions can be carried out under heterogeneous conditions and examination of a series of diesters has shown dihydrocinnamyl to be the most satisfactory of the hydroxyl protecting groups evaluated so far. The degree of specificity achievable is demonstrated by the fact that α-chymotrypsin-catalyzed hydrolysis of 2-acetoxyethyl dihydrocinnamate at pH 7.8 stops when the latter function has been cleaved. In addition, some guidelines have been developed regarding the application of literature specificity data for predicting the course and rate of preparative scale reactions.