17O NMR Spectra of Divinyl Ethers

Abstract

The 17O NMR spectra of a number of alkyl- and phenyl-substituted divinyl ethers were recorded in CDCl3 solution. The relationship between chemical shift and the number, nature and position of substituents was explored. The shift values, falling in the range δ 100–140 ppm, were found to be remarkably insensitive to the electronic and stereochemical effects of substituents. The narrow range of chemical shifts is likely to arise from the ability of the O atoms of divinyl ethers to share p–π conjugation with the two olefinic linkages: reduced conjugation with one vinyl group may lead to enhanced conjugation with the other. © 1997 by John Wiley & Sons, Ltd.