for example the acid chloride starting material could be reacted with the protected glucopyranose in the presence of suitable bases other than pyridine e g other tertiary aliphatic or aromatic amines such as n methylmorpholine triethylamine and picoline conveniently in a non protic solvent alternatively the protected glucopyranose could be reacted with 2 acetoxybenzoic acid rather than with the acid chloride in which case the reaction would be conducted in the presence of a suitable dehydrating agent for example an aromatic or aliphatic carbodiimide the rate of generation of aspirin via hydrolysis of its derivatives of the present invention can be determined spectrophotometrically determination of rate of generation of aspirin from its pro drugs according to the present invention were made using solutions ranging from ph 1 2 to ph 9 the generation of aspirin from the derivatives was found to be largely independent of the ph of the solutions the half life for the hydrolysis at ph 3 and ph 8 at 37 u00b0 c was found to be in the range of several minutes e g between 5 and 10 minutes thus the transient blocking of the acidic carboxylic group of aspirin by formation of an acylal linked derivative results in a compound which regenerates aspirin at an acceptable rate such a compound reduces the gastrointestinal liability of aspirin by presenting a neutral molecule.