title: Efficient routes to epimerically-pure side-chain derivatives of lanosterol.
abstract: A technically simple route is described to individual epimers of side-chain derivatives of lanosterol (3beta-hydroxy-5alpha-lanosta-8,24-diene). Epimerically pure 24,25-epoxy-, 24,25-dihydroxy- and 24-bromo-25-hydroxy-lanosterol have been prepared in good yield from commercial (50-60%) lanosterol. Hypophosphorous acid was used as a catalyst for the cohalogenation of the Delta24(25) bond and also for the efficient conversion of 24,25-epoxy- and 24-bromo-25-hydroxylanosterol to epimerically pure 24(R) or 24(S)-24,25-dihydroxylanosterols.
authors.affiliation: Department of Chemistry, University of Waikato, Private Bag 3105, Hamilton, New Zealand.
authors.forename: Levan K
authors.initials: LK
authors.lastname: Kavtaradze
authors.forename: Merilyn
authors.initials: M
authors.lastname: Manley-Harris
authors.forename: Brian K
authors.initials: BK
authors.lastname: Nicholson
mesh_terms: D000107:Acetylation; D000475:Alkenes / Q000737:chemistry; D002247:Carbon Isotopes; D002384:Catalysis; D002849:Chromatography, Gas; D004467:Economics; D004852:Epoxy Compounds / Q000737:chemistry; D007536:Isomerism; D007810:Lanosterol / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010721:Phosphinic Acids / Q000737:chemistry; D011522:Protons; D013329:Structure-Activity Relationship
chemical_list: D000475:Alkenes; D002247:Carbon Isotopes; D004852:Epoxy Compounds; D010721:Phosphinic Acids; D011522:Protons; D007810:Lanosterol