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· 2H 2 O 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 ...