Synthesis and structures of partially unsaturated thiacrown ethers with hydroxyl groups

Abstract

Partially unsaturated 14- and 28-membered thiacrown ethers possessing hydroxyl groups were synthesised. The crystal structures of some geometrical isomers of the macrocycles were determined by X-ray crystallographic analysis and six oxygen atoms of the 14-membered trans-thiacrown ether were found to gather through hydrogen bonds in the crystalline state. The redox behaviours of the 14-membered thiacrown ethers were examined and the Z,E-isomerisation reactions were found to occur upon heating.