1431-63-6Relevant academic research and scientific papers
1H and 13C NMR Assignments for Lanostan-3β-ol Derivatives: Revised Assignments for Lanosterol
Emmons, Gary T.,Wilson, William K.,Schroepfer, George J. Jr
, p. 1012 - 1024 (2007/10/02)
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
TETRACYCLIC TRITERPENES. X. SOLVENT EFFECT IN REACTIONS OF TETRASUBSTITUTED TRITERPENOIDAL OLEFINS WITH OZONE. AN ALLYLIC OXIDATION
Paryzek, Zdzislaw,Martynow, Jacek
, p. 2130 - 2136 (2007/10/02)
The highly hindered 8,9 double bond in lanostane derivatives was found susceptible to oxidation with ozone.The reaction depends on the polarity of the solvent.It is proposed that the structure of the initial complex formed between the olefin and ozone is influenced by the reaction medium.Reaction of 3β-acetoxy-5α-lanost-8-ene with ozone gives 8α,9α-epoxide in methylene chloride, while 3β-acetoxy-5-α-lanost-8-en-7-one, an allylic oxidation product, is the main compound formed in ethyl acetate.
