Principal component analysis was applied to the 13C NMR chemical shifts of the seven carbon atoms of the norbornyl framework for 75 molecules. Two two-dimensional principal component projections are shown to be sufficient to distinguish the main electronic and steric substituent effects contributing
Principal component analysis of the 13C NMR shifts of norbornyl derivatives. II—tetracyclic dodecane derivatives
✍ Scribed by José Glauco Ribeiro Tostes; Peter Rudolf Seidl; Kátia Zaccur Leal; Roy Edward Bruns
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 490 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
Principal component analysis is applied to the ^13^C NMR chemical shifts of 29 tetracyclic dodecane derivatives, the spectra of most of which have been recently assigned. These derivatives are subdivided into three classes: exo‐endo, exo–exo and endo–endo. Only the seven ^13^C shifts of one of the two norbornyl moieties of these derivatives are used in the construction of the data matrix, the other moiety being considered as a ring substituent. This data treatment allows these 29 systems to become a test system for a previously worked (through principal component analysis) standard or training set of ^13^C shifts of 55 substituted norbornanes. Only one two‐dimensional principal component projection is necessary for identifying the main structural effects in the chosen norbornyl moiety of the test system, highlighting trends in the ^13^C data of these test derivatives and confirming their recent ^13^C spectral assignments.
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