Synthesis of thiacrown and azacrown ethers based on a spiroacetal framework

A novel class of thiacrown and azacrown ethers incorporating the 1,7-dioxaspiro[5.5]undecane spiroacetal ring system was prepared by reaction of ditosylate 5 with the appropriate dithiols 9a–c or protected diamine 12a. Spiroacetal ditosylate 5 in turn, was prepared from diol 3 via ozonolysis of bisallyl ether 7 followed by tosylation of the derived diol 8.