1H and 13C NMR Assignments for Lanostan-3β-ol Derivatives: Revised Assignments for Lanosterol

Article abstract of DOI:10.1002/mrc.1260271103

1H and 13C NMR assignments are presented for 30 oxygenated lanostane derivatives, including lanosterol, dihydrolanosterol, 7-ketolanosterol, agnosterol, 24,25-epoxylanosterol, 8α,9α-epoxylanostan-3β-ol, three 15-oxygenated derivatives of lanost-7-en-3β-ol, lanostane-3β,7α-diol, lanostane-3B,9α-diol and their acetates.These assignments, which were largely determined by a combination of DEPT, one-bond and long-range 13C-1H chemical shift correlation and lanthanide-induced shift experiments, are not dependent on previously reported assignments, several of which were found to be incorrect. 1H and 13C acetylation shifts for lanostan-3β-ols were sufficiently invariant among the sterols studied that they were useful for assigning carbons in rings A and B.The acetylation shifts reported for lanostan-3β-ols were extended and partially revised.-- Key Words 1H and 13C NMR Oxygenated lanostane derivatives Spectral assignment Lanthanide-induced shifts Long-range HECTOR Acetylation shifts