- Photochemistry of 3H-furo[3,4-c]pyrazoles and 3H-thieno[3,4-c]pyrazoles
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The first examples of 3H-furo[3,4-c]pyrazoles and 3H-thieno[3,4-c]pyrazoles were prepared in an attempt to isolate examples of cyclopropane-fused thiophenes and furans. Adducts of acetylenic ketones and 2-diazopropane were reacted with 10-camphorsulfonic acid or phosphorus pentasulfide to produce the title compounds. Photolysis of these compounds did not give the cyclopropane-fused products rather an unreported photochemical fragmentation was observed.
- Payne, Alan D.
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- 1,4-Conjugate additions of methoxyamine and 1,1-dimethylhydrazine to hex-3-yne-2-one: A facile synthesis of functionalized isoxazole and pyrazole precursors
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When hex-3-yne-2,5-dione (2) was reacted with either methoxyamine or 1,1-dimethylhydrazine, the 1,4-addition products 4 and 7 were isolated in yields of 89% and 48% respectively. Copyright Taylor & Francis, Inc.
- Sauers, Ronald R.,Van Arnum, Susan D.
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p. 2033 - 2038
(2007/10/03)
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- Selective oxidation of acetylenic 1,4-diols with dioxiranes in comparison with the methyltrioxorhenium-hydrogen peroxide oxidant
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Dimethyldioxirane (DMD) and its trifluoro analog (TFD) were employed to achieve selectively the direct transformation of diol 3a and of diol 3b into the corresponding carbonyls. The results are compared with oxidations using methyltrioxorhenium (MTO)/85%
- D'Accolti, Lucia,Fiorentino, Michele,Fusco, Caterina,Crupi, Pasquale,Curci, Ruggero
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p. 8575 - 8578
(2007/10/03)
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- A convenient preparation of 3-Acetyl-5-methylisoxazole
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Starting from 2,5-hexanedione (4), a one-pot preparation of 3-acetyl-5-methylisoxazole (1) is described. 3-Acetyl-5-methylisoxazole (1) is a useful compound for the preparation of 3-oxobutyronitrile (10) and for 3-vinyl-(5-methyl isoxazolyl) ketone (2).
- Sauers, Ronald R.,Van Arnum, Susan D.
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p. 655 - 658
(2007/10/03)
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- Synthesis and reactivity of 2,4,4-trimethyl-2-silylethynyl substituted 1,3-dioxanes
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A synthesis was developed for 2,4,4-trimethyl-2-ethynyl substituted 1,3-dioxane. Hydrolysis and cleavage thereof at the Si-Csp bond was investigated.
- Kosulina,Ol'khovskaya,Kul'nevich
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p. 608 - 613
(2007/10/03)
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- Stereoselective reduction of unsaturated 1,4-diketones. A practical route to chiral 1,4-diols
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A new synthetic route to C2-symmetric chiral 1,4-diols based on the borane-mediated oxazaborolidine-catalysed reduction of 2-ene-1,4-diones (2), of 2-yne-1,4-diones (3), and/or of Co-complexed diketones 4 is described. Good to excellent enantio- and diastereoselectivities have been obtained in the reduction of diketones 3 and 4, catalysed by oxazaborolidines 6 and 5, respectively.
- Bach, Jordi,Berenguer, Ramon,Garcia, Jordi,Loscertales, Teresa,Manzanal, Judith,Vilarrasa, Jaume
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p. 1091 - 1094
(2007/10/03)
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- Zeolite-catalyzed oxidation of benzylic and acetylenic alcohols with t-butyl hydroperoxide
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4 A molecular sieves catalyze the mild conversion of activated secondary alcohols into the corresponding carbonyl compounds with t-butyl hydroperoxide (TBHP).
- Palombi, Laura,Arista, Luca,Lattanzi, Alessandra,Bonadies, Francesco,Scettri, Arrigo
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p. 7849 - 7850
(2007/10/03)
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- N- and O-substituted aminophenols, method and use for diagnosis
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The present invention provides N- and O-substituted aminophenol derivatives of the general formula STR1 wherein R1, R2, R3, G and L are as hereinbefore defined. The present invention also provides intermediates for the preparation of these aminophenol derivatives of general formula (I), as well as the use of the aminophenol derivatives of general formula (I) for the determination of hydrolyses, as well as for the preparation of agents for carrying out determinations of hydrolyses.
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- Organic Heterocyclothiazenes. Part 5. Cycloaddition Reactions of Tetrasulphur Tetranitride with Highly Electron Deficient Alkynes
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In contrast with previous, complex, S4N4-alkyne reactions, treatment of butynedinitrile and S4N4 is found to give 1,3,5,2,4-trithiadiazepine-6,7-dicarbonitrile (8) and 1,2,5-thiadiazole-3,4-dicarbonitrile (9) very cleanly and in high yield.Hexafluorobut-2
- Dunn, Peter J.,Rees, Charles W.
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p. 1579 - 1584
(2007/10/02)
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