ISSN:
0749-1581
Keywords:
Conformational transmission
;
Diastereotopic proton assignment
;
NMR conformational analysis
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A new method is presented for the assignment of the NMR resonances of the diastereotopic protons in tetrahydrofur-furyl and pyrrolidinylmethyl groups, based on the conformational transmission effect This effect describes the conformational changes produced by an increase of coordination from four to five of a phosphorus, silicon or germanium atom attached to the tetrahydrofurfuryl or pyrrolidinylmethyl moieties. The 1H NMR conformational analysis of these cyclic four- and five-coordinated compounds yields two possible results, based on two assignments of the diastereotopic proton resonances. Comparison with the conformations of the analogous four- and five-coordinated systems with acyclic 2-methoxyethyl and dimethylaminoethyl groups (which lack diastereotopic protons) directly shows which assignment is correct, since a similar conformational transmission occurs in both the cyclic and the acyclic compounds.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260251009
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