Abstract
In order to investigate a new type of promoiety for ampicillin prodrugs, acyloxyallyl esters were prepared and their oral absorbabilities, stabilities and hydrolyzabilities to parent ampicillin were studied. As starting materials for (3-phthalidylidene)ethyl esters, ethylidenephthalide and its derivatives were regiospecifically prepared by a new method using the Wittig reaction. (3-Phthalidylidene)ethyl esters (14a-c) given orally were well absorbed, but (thiophthalidylidene)ethyl ester (14d) and (isocoumarin-4-yl)methyl ester (14e) were poorly absorbed.
