1.
Org Lett
; 22(5): 1714-1719, 2020 03 06.
Artigo
em Inglês
| MEDLINE
| ID: mdl-32068413
RESUMO
The current scientific consensus generally assigns incorrect C20 configurations to taraxastane-3ß,20-diols and their oxo derivatives reported in 32 articles. Definitive configurations established here by NOESY, quantum mechanical NMR predictions, and 13C NMR γ-gauche effects warrant updating of the many erroneous structures. Suggestions to improve NMR structure determinations of such nonpolar polycyclic natural products include acquiring 2D spectra at higher resolution, suppressing zero-quantum coherence in NOESY, and judging proposed NOE correlations against H-H distances.