- Regioselective dehydrogenation of 3-keto-steroids to form conjugated enones using o-iodoxybenzoic acid and trifluoroacetic acid catalysis
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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 (Δ1- and Δ4-3- 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.
- Iida, Takashi,Omura, Kaoru,Sakiyama, Ryou,Kodomari, Mitsuo
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- Synthesis of Triaromatic Steroid Hydrocarbons Methylated at Position 2, 3 or 6: Molecular Fossils of Yet Unknown Biological Origin.
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C21-29 triaromatic steroid hydrocarbons bearing a methyl group at unusual positions 2, 3 or 6 have been synthesized from pregnenolone, cholesterol or stigmasterol via stera-3,5-dienes.Their occurence in various sedimentary rocks and petroleums suggests the presence of yet unknown biological precursors.
- Lichtfouse, Eric,Albrecht, Pierre
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p. 1731 - 1744
(2007/10/02)
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- OCCURRENCE OF 2-METHYL-, 3-METHYL- AND 6-METHYLTRIAROMATIC STEROID HYDROCARBONS IN GEOLOGICAL SAMPLES.
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Triaromatic steroid hydrocarbons bearing a methyl substituent at position 2, 3, or 6 have been identified in marine sediments and petroleums from the Paris basin by comparison with C21 (1, 2, 3), C27 (4) and C29 (5) synthetic standards.Due to their formation with depth they are useful for maturity studies.
- Lichtfouse, E.,Riolo, J.,Albrecht, P.
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p. 3937 - 3940
(2007/10/02)
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