Synthesis of novel biscrown ethers with rigid cis/trans ethylene bridge

Two novel biscrown ethers with rigid cisltrans ethylene linker were synthesized v/a Wittig reaction in high yield (about 80%).Their pure cis/trans-isomers were obtained by column chromatography separation. And their structure/configuration was confirmedby 1H NMR, 13C NMR, ESI mass spectrum, elemental analysis and UV-vis spectra.? 2008 La Sheng Jiang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.