- Ruthenium dioxide in fluoro acid medium V. Application to the non phenolic oxidative coupling of diarylbutanes. Conformational studies of cis and trans deoxyschizandrins
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Ruthenium (IV) dioxide dihydrate in fluoro acidic medium was found to be a very efficient agent for the non phenolic oxidative coupling of diarylbutanes. We observed along with the expected aryl-aryl coupling, an unusual aryl-benzyl coupling, leading to a known class of lignans, the aryltetralins. Conformational studies of resultant cis and trans deoxyschizandrins were performed using high resolution NMR and molecular models.
- Dhal,Landais,Lebrun,Lenain,Robin
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p. 1153 - 1164
(2007/10/02)
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- Intramolecular Oxidative Coupling of Aromatic Compounds. IV. Oxidation of Non-Phenolic Substrates
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Intramolecular non-phenolic coupling of (2RS,3SR)-1,4-bis(4-benzyloxy-3,5-dimethoxyphenyl)-2,3-dimethylbutan-1-one (6) failed.Oxidation of the derived butane (9) gave the aryltetralin (14) in low yield.
- Krauss, Adrian S.,Taylor, Walter C.
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p. 935 - 939
(2007/10/02)
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- Intramolecular Oxidative Coupling of Aromatic Compounds. II. The Synthesis of (2RS,3SR)- and (2RS,3RS)-2,3-Dimethyl-1,4-bis(3,4,5-trimethoxyphenyl)butan-1-one and the Determination of Stereochemistry
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The C-methylation of 3-methyl-1,4-bis(3,4,5-trimethoxyphenyl)butan-1-one (9) gave in a ratio of 4:1 the diastereoisomers, (2RS,3SR)- and (2RS,3RS)-2,3-dimethyl-1,4-bis(3,4,5-trimethoxyphenyl)butan-1-one, (7) and (8) respectively.The stereochemistry of eac
- Krauss, Adrian S.,Taylor, Walter C.
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p. 1335 - 1340
(2007/10/02)
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- SYNTHESIS OF DIARYLBUTANES FROM CORDIGERINES AND REINVESTIGATION OF THEIR OXIDATIVE COUPLINGS IN DEOXYSCHIZANDRINS. - AN UNUSUAL FORMATION OF PHENYLTETRALIN LIGNANS -
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Dibenzylbutanolide lignans including cordigerines were synthetized and transformed in the corresponding diarylbutane lignans which were submitted to non-phenolic oxidative coupling conditions by using RuO2 or Tl2O3 in trifluoroacetic medium to give deoxyschizandrins.A concurently aryl-benzyl coupling leads to the formation of the corresponding phenyltetralin of which the structure was confirmed by total synthesis.
- Landais, Y.,Lebrun, A.,Lenain, V.,Robin, J.-P.
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p. 5161 - 5164
(2007/10/02)
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- New Reagent System containing CrO3 and Syntheses of Neo-lignans
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Oxidations of 1-arylprop-1-enes by the new reagent systems, CrO3-HBF4-MeCN or CrO3-HClO4-MeCN gave the 4-aryltetralones (1a) and (1c), and the tetrahydrofuran (3) which are precursor molecules for aryltetrahydronaphthalene and tetrahydrofuran neo-lignans.
- Takeya, Tetsuya,Kotani, Eiichi,Tobinaga, Seisho
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- New Reagent Systems Containing CrO3 Provide Precursors for Syntheses of Neo-lignans
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Oxidations of 1-aryl-1-propenes with new reagent systems, CrO3-HBF4-MeCN and CrO3-HClO4-MeCN, gave the 4-aryltetralones 1a and 1c, and the tetrahydrofuran 4, which are precursor molecules for aryltetrahydronaphthalene and tetrahydrofuran neo-lignans.Keywords - reagent system: chromium trioxide, neo-lignan; aryltetrahydronaphthalene; tetrahydrofuran
- Takeya, Tetsuya,Matsumoto, Hiroshi,Kotani, Eiichi,Tobinaga, Seisho
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p. 4364 - 4367
(2007/10/02)
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