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Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers

[Image: see text] Conjugation can lower the energy barrier for unsaturated C–C bond rotations, resulting in a mixture of equilibrating diastereomers at room temperature. Therefore, methods claiming diastereoselective synthesis of conjugated double bonds often require proof that the observed diastere...

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Autores principales: Hussaini, Syed Raziullah, Kuta, Adama, Pal, Arpan, Wang, Zhiguo, Eastman, Margaret A., Duran, Ramon
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2020
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7528312/
https://www.ncbi.nlm.nih.gov/pubmed/33015503
http://dx.doi.org/10.1021/acsomega.0c03554
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author Hussaini, Syed Raziullah
Kuta, Adama
Pal, Arpan
Wang, Zhiguo
Eastman, Margaret A.
Duran, Ramon
author_facet Hussaini, Syed Raziullah
Kuta, Adama
Pal, Arpan
Wang, Zhiguo
Eastman, Margaret A.
Duran, Ramon
author_sort Hussaini, Syed Raziullah
collection PubMed
description [Image: see text] Conjugation can lower the energy barrier for unsaturated C–C bond rotations, resulting in a mixture of equilibrating diastereomers at room temperature. Therefore, methods claiming diastereoselective synthesis of conjugated double bonds often require proof that the observed diastereomeric ratio is not because of the diastereomeric equilibration of the product. Variable-temperature (VT) NMR experiments are commonly used to distinguish between the two possibilities. However, the VT technique requires accessories for the NMR spectrometer and more setup time. Here, we show that the rarely used application of 1-D and 2-D nuclear Overhauser effect spectroscopy experiments for the detection of the equilibrating diastereomers is a convenient alternative to the VT technique.
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spelling pubmed-75283122020-10-02 Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers Hussaini, Syed Raziullah Kuta, Adama Pal, Arpan Wang, Zhiguo Eastman, Margaret A. Duran, Ramon ACS Omega [Image: see text] Conjugation can lower the energy barrier for unsaturated C–C bond rotations, resulting in a mixture of equilibrating diastereomers at room temperature. Therefore, methods claiming diastereoselective synthesis of conjugated double bonds often require proof that the observed diastereomeric ratio is not because of the diastereomeric equilibration of the product. Variable-temperature (VT) NMR experiments are commonly used to distinguish between the two possibilities. However, the VT technique requires accessories for the NMR spectrometer and more setup time. Here, we show that the rarely used application of 1-D and 2-D nuclear Overhauser effect spectroscopy experiments for the detection of the equilibrating diastereomers is a convenient alternative to the VT technique. American Chemical Society 2020-09-16 /pmc/articles/PMC7528312/ /pubmed/33015503 http://dx.doi.org/10.1021/acsomega.0c03554 Text en This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Hussaini, Syed Raziullah
Kuta, Adama
Pal, Arpan
Wang, Zhiguo
Eastman, Margaret A.
Duran, Ramon
Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title_full Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title_fullStr Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title_full_unstemmed Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title_short Application of NMR Spectroscopy for the Detection of Equilibrating E–Z Diastereomers
title_sort application of nmr spectroscopy for the detection of equilibrating e–z diastereomers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7528312/
https://www.ncbi.nlm.nih.gov/pubmed/33015503
http://dx.doi.org/10.1021/acsomega.0c03554
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