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 .
C0015060
ethyl ethers
C0014996
ethers