The current scientific consensus generally assigns incorrect C20 configurations to taraxastane-3β,20-diols and their oxo derivatives reported in 32 articles. Definitive configurations established here by NOESY, quantum mechanical NMR predictions, and 13 C 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. * sı Supporting InformationThe Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.orglett.9b04566.Experimental methods, isolation of 1−3, GC-MS and NMR spectra, NMR tables, NOESY integrals, DFT-GIAO NMR calculations, and the code for the t1away program (PDF) Raw_nmr_data.zip (ZIP)