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Long-range proton-proton interactions through epoxides

✍ Scribed by P. Joseph-Nathan; E. Díaz

Publisher
John Wiley and Sons
Year
1971
Tongue
English
Weight
455 KB
Volume
3
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Double and triple nuclear magnetic resonance experiments performed at 100 MHz demonstrate the existence of long range ^1^H—^1^H couplings through epoxides. In a series of epoxycontaining sesquiterpenoids, interactions between protons separated by up to six sigma bonds were detected. These interactions may have origins similar to the well‐known allylic and homoallylic couplings found in carbon‐carbon double bonded compounds, although they are much smaller in the epoxy systems. We propose to name them as ‘epoallylic’ and ‘epohomoallylic’ interactions. Some couplings are observed directly, whereas in other cases only an improvement in resolution is seen during multiple irradiation experiments. Even in these latter cases the areas of the observed peak do not change upon multiple irradiation which demonstrates the absence of nuclear Overhauser effects. The stereochemistry of some asymmetric centers of the compounds studied is deduced from the spectra.

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