ISSN:
0749-1581
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 13C NMR spectrum of the pentacyclic triterpene friedelin was fully assigned, taking into account signal multiplicities, correlations of the carbon lines with known proton resonances and Eu-induced shifts. This work clarifies the situation prevalent in the literature, in which three separate groups have published contradictory information. In addition, the carbon and proton spectra of the naturally occurring 3α-hydroxyfriedelan-2-one and its synthetic acetate were analysed. The different preferred conformations of the D/E rings for friedelin (boat-boat) and polpunonic acid (chair-chair) are rationalized.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260230805
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