CYCLODEXTRIN CATALYZED-HYDROLYSIS OF GUAJ ACOLESTERS AND VANILLYLESTERS OF PHENYLALCANOIC ACIDS

Cyclodextrins (CDs) catalyse the hydrolysis of guajacol- and vanillyle sters of phenylalcanoic acids in different ways. Whereas beta-CD raise the rate constant, it takes off in alpha- and gamma-CD. Methyl-beta-C D slow down the cleavage of the esters. The effect is pronounced more clearly at the higher phenylbutyric ester than at the phenylpropionic ester. The a hundred times higher acidity of the vanillylester causes a slight cleavage of the vanillylester and a smaller effect of CD, but the inhibition is very distinct. A displacement of the substance from its CD-bonding by means of 2-butanol could not be observed.