Functionalized macrocycles. I. Synthesis of thiol-bearing crown ethers as an approach to regioselective catalysts.

Abstract

The rates of transacylation were studied between crown ethers (1, 2, 3) having sulfhydryl groups at the end of side arms of different lengths and α-, β-, γ-, and e-amino acid p-nitrophenyl ester salts (4, 6, 7, 8). It was shown that regioselectivity of the reaction can be successfully correlated with the distance of the catalytic site from the polyether ring. It was also shown that introduction of ether oxygen in the side arm can be used to keep the side arm sticking up from the polyether ring in the complex.