Synthesis and Stereochemistry of Thiacrown Ethers with Unsaturated Bonds

Abstract

Partially unsaturated 14- and 28-membered thiacrown ethers with Z-olefins were synthesized. The crystal structures of some of the macrocycles were determined by X-ray crystallographic analysis, and the 28-membered thiacrown ethers were found to have slender structures in the crystalline state. The 14-membered thiacrown ether without any substituent was found to be oxidized more easily than the corresponding thiacrown ether possessing hydroxyl groups. Heating of the 14-membered macrocycles was found to cause the Z,E-isomerization reactions to give the corresponding E,Z- and E,E-isomers.