Crown and azacrown ethers with pendant adenine group

Abstract

Base-catalyzed oxirane ring-opening reaction of 4,5-epoxy-2-oxapentyl crown ethers Ia-Ie and N-(2,3-epoxy-1-propyl) azacrown ethers IIa-IIc with adenine affords mixtures of corresponding adenin-9-yl, adenin-3-yl and adenin-7-yl derivatives (IIIa-IIIe, IVa-IVe, Va-Ve, VIa-VIc, VIIa-VIIc and VIIIa-VIIIc) respectively, separable by liquid chromatography. Structure of the individual isomers was assigned on basis of 1H, and 13C NMR spectroscopy. Compexation of the prevailing (adenin-9-yl) isomers IIIa-IIIe and VIa-VIc with sodium ion was measured potentiometrically in 99% methanol and the calculated stability constants were compared with corresponding data from related homologous series of crown and azacrown ethers IXa-IXe, Xa-Xe, XIa-XIc and XIIa-XIIc differing in pendant group.