title: Regioselective dehydrogenation of 3-keto-steroids to form conjugated enones using o-iodoxybenzoic acid and trifluoroacetic acid catalysis.
abstract: Mild and regioselective conversion of 3-keto-5α- and 3-keto-5β-steroids (trans A/B- and cis A/B-ring juncture, respectively) to the corresponding enones (Δ(1)- and Δ(4)-3-ketones) by treatment with o-iodoxybenzoic acid (IBX) catalyzed by trifluoroacetic acid (TFA) in DMSO, is described. The IBX-mediated reaction involved dehydrogenation of the α- and β-hydrogen atoms of the 3-ketones to give the enones regioselectively in good isolated yields without concomitant formation of related dienones and trienones.
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan. Electronic address: takaiida@chs.nihon-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iida
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Omura
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Ryou
authors.initials: R
authors.lastname: Sakiyama
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kodomari
mesh_terms: D004121:Dimethyl Sulfoxide / Q000737:chemistry; D007462:Iodobenzenes / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D007664:Ketosteroids / Q000737:chemistry*; D013237:Stereoisomerism; D014269:Trifluoroacetic Acid / Q000737:chemistry*
chemical_list: D007462:Iodobenzenes; D007659:Ketones; D007664:Ketosteroids; C476101:o-iodoxybenzoic acid; D014269:Trifluoroacetic Acid; D004121:Dimethyl Sulfoxide
keywords: High-resolution atmospheric pressure chemical ionization mass spectrometry (HR-APCI-MS); High-resolution electrospray ionization mass spectrometry (HR-ESI-MS); Nuclear magnetic resonance (NMR); Thin-layer chromatography (TLC); Trifluoroacetic acid (TFA); o-Iodoxybenzoic acid (IBX)