title: Sterol metabolism: XXXIII. On derivation of cholesterol 7-alkoxyl ethers.
abstract: The facile acid-catalyzed conversion of cholest-5-ene-3 beta, 7 alpha-diol (but not of cholest-5-ene-3 beta, 7 beta-diol) in methanol or ethanol solution to the corresponding 7 alpha-methyl or 7 alpha-ethyl ethers and epimerization of the 7 alpha-alkyl ethers to the corresponding 7 beta-alkyl ethers were established. The epimeric cholest-5-ene-3 beta, 7-diols, their 7-methyl ethers, and their 7-ethyl ethers are readily interconverted in acidified solvents, the quasiequatorial 7 beta-epimer predominating in each case. Both 7 alpha- and 7 beta-alkyl ethers may be encountered as artifacts in analyses of sterol mixtures from mamalian tissues.
mesh_terms: D001011:Aorta / Q000032:analysis; D002784:Cholesterol / Q000032:analysis*; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004987:Ethers; D006801:Humans; D013058:Mass Spectrometry; D008722:Methods; D013055:Spectrophotometry, Infrared
chemical_list: D004987:Ethers; D002784:Cholesterol