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Connecting Discrete Stereoclusters by Using DFT and NMR Spectroscopy: The Case of Nivariol
Author(s) -
CenPacheco Francisco,
Rodríguez Jaime,
Norte Manuel,
Fernández José J.,
Hernández Daranas Antonio
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201204272
Subject(s) - chemical shift , molecule , chemistry , computational chemistry , nuclear magnetic resonance spectroscopy , spectroscopy , population , carbon 13 nmr , carbon 13 nmr satellite , interpretation (philosophy) , fluorine 19 nmr , stereochemistry , organic chemistry , physics , computer science , demography , quantum mechanics , sociology , programming language
The structural determination of small organic molecules is mainly undertaken by using NMR techniques, although it is increasingly supplemented by using computational methods. NMR parameters, such as chemical shifts and coupling constants, are extremely sensitive indicators of local molecular conformation and are a source of structural evidence. However, their interpretation is fairly challenging in many circumstances, such as the case of the new polyether squalene derivative nivariol, the structure of which was elucidated by means of NMR spectroscopy and DFT calculations. The potential flexibility of this molecule and the high number of quaternary carbon atoms that it contains make its configurational assignment very difficult. Moreover, the relative configuration of four separated stereoclusters was established and subsequently connected by using NOE and J ‐based analysis, as well as by a comparison of its experimental 13 C NMR chemical shifts with the corresponding population‐weighted values, as calculated by using DFT methods. Limitations of these used approaches became apparent but were overcome by combining the two methods.