Abstract
It has been found that monothiuronium salts derived from ω, ω'-dichloropoly (oxyethylene) and thiourea were treated with sodium hydroxide in ethyl alcohol to give monothiacrown ethers in much higher yield than those attained by the known method of thiacrown ether synthesis, Monothia-15-crown-5, -18-crown-6 and their homologs with high alkyl (C8C12) group were conveniently prepared in good yields with use of the new method.
Catalytic action on the reduction of 2-octanone with saturated aqueous sodium borohydride was examined for these products. The catalytic efficiency increased with the increasing ring size and alkyl chain length of the macrocycle. The efficiency of decyl-monothia-18-crown-6 was found to be comparable to that of perhydrodibenzo-18-crown-6. However, these alkylthiacrown ethers showed no catalytic action on the substitution reaction of octyl bromide with aqueous potassium iodide.
