Synthesis and Alkali-cation Complexing Properties of 12-Crown-4 Derivatives

Abstract

Abstract Benzyloxymethyl-12-crown-4, a precursor of hydroxymethyl-12-crown-4, is prepared in an excellent yield by the reaction of 3-benzyloxy-1,2-propanediol with 1,8-dichloro-3,6-dioxaoctane in the heterogeneous t-BuOLi/t-BuOH/LiBr·2H2O reaction system. The hydrogenolysis in the presence of p-toluenesulfonic acid leads to a good yield of hydroxymethyl-12-crown-4. The sandwich-type 2:1 complexation with Na+ of 12-crown-4 and hydroxymethyl-12-crown-4 derivatives was discussed on the basis of the stability constants and the solvent extraction in the CH2Cl2–water system.