title: A facile one-step synthesis of delta 1,4-3-keto bile acid esters by iodoxybenzene and benzeneselenic anhydride.
abstract: A facile one-step conversion of stereoisomeric methyl 3-hydroxycholanoates to 1,4-dien-3-one, by treatment in boiling toluene with iodoxybenzene catalyzed by benzeneselenic anhydride, is described. The direct oxidation-dehydrogenation at C-3 is applicable to other cholanoates (hyodeoxycholic, chenodeoxycholic, ursodeoxycholic, deoxycholic, and cholic) when the hydroxyl groups at C-6, C-7, or C-12 are protected. Without protection at C-6 and C-7, the products from hyodeoxycholic, chenodeoxycholic, ursodeoxycholic, and cholic esters are complex mixtures, whereas, methyl deoxycholate yields the 1,4-dien-3,12-dione cleanly.
authors.affiliation: College of Engineering, Nihon University, Fukushima-ken, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Iida
authors.forename: T
authors.initials: T
authors.lastname: Shinohara
authors.forename: J
authors.initials: J
authors.lastname: Goto
authors.forename: T
authors.initials: T
authors.lastname: Nambara
authors.forename: F C
authors.initials: FC
authors.lastname: Chang
mesh_terms: D001555:Benzene Derivatives; D001647:Bile Acids and Salts / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D004952:Esters; D007462:Iodobenzenes; D016566:Organoselenium Compounds; D010084:Oxidation-Reduction; D012643:Selenium
chemical_list: D001555:Benzene Derivatives; D001647:Bile Acids and Salts; D004952:Esters; D007462:Iodobenzenes; D016566:Organoselenium Compounds; C057599:benzeneselenic anhydride; C057598:iodoxybenzene; D012643:Selenium