Fraser, Robert R.; Raby, Bruce F. published an article in 1972, the title of the article was Substituent effect on geminal coupling constants in allylic methylene groups.Product Details of 37480-41-4 And the article contains the following content:
The geminal proton-proton coupling constants were determined for the allylic methylene protons in a series of selectively deuterated cyclohexene derivatives The effect of substituents β to the methylene group on 2J agrees with theoretical calculations Electron-withdrawing substituents cause a neg. shift and electron-donating substituents cause a pos. shift in 2J, the total variation being 2.9 Hz. This effect is larger than that exerted by para substituents in benzylic systems as would be expected for a more polarizable double bond. The 2J’s correlate poorly with the existing substituent parameters but correlate well with the shift of the olefinic protons adjacent to the double bond. This correlation is interpreted as evidence that the change in 2J is produced primarily by a resonance interaction of the substituent with the double bond resulting in a change in the hyperconjugative withdrawal of electrons from the adjacent methylene group. The experimental process involved the reaction of Methyl 1-methyl-4-oxocyclohexanecarboxylate(cas: 37480-41-4).Product Details of 37480-41-4
The Article related to substituent effect nmr allylic methylene, Physical Organic Chemistry: Spectral and Related Studies and other aspects.Product Details of 37480-41-4
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