Ester interchange using molecular sieves

Ester interchange reactions using type A molecular sieves which selectively adsorb the displaced alcohol, have been shown to proceed practically to completion. Examples are given which cover a number of starting esters, displacing alcohols, experimental procedures, solvents, and cationic forms of the molecular sieves. Several new t-butyl esters were obtained and characterized. Equilibrium constants were measured and rate studies made for several representative reactions. The interaction of sodium and potassium isopropoxide catalysts and sieves has also been investigated. Both cation exchange with the sieves and adsorption of alkoxide after the addition of methyl alcohol have been observed. Interesting differences have been found between 3A, 4A, and 5A sieves. The interfering dehydration of t-butyl alcohol has been studied with different molecular sieves of type A. The influence of traces of water and triethylamine on the dehydration has been investigated.