Synthesis of Substituted Crown Ethers from Oligoethylene Glycols

Article abstract of DOI:10.1021/jo01314a030

A convenient synthetic method for preparing 12-crown-4, 15-crown-5, 18-crown-6, and 21-crown-7 bearing various substituents by intramolecular cyclization of the corresponding substituted oligoethylene glycols in high yields is described.Substituents include modifiable pendent groups such as phenyl and hydroxymethyl, as well as various alkyl groups.Stability constants for the new substituted crown ethers with sodium and potassium ions in methanol were determined by potentiometric titration.The absolute effect of pendent groups on stability constants was insignificant.