- Reactions of CH-acids with α,β-unsaturated aldehydes in ionic liquids
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Metal carbonate-catalyzed reactions of CH-acids (diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, and ethyl 2-acetyl- and 2-ethoxycarbonyl-5,9- dimethyldeca-4,8-dienoates) with α,β-unsaturated aldehydes (acrolein, crotonaldehyde, citral) were studied in an ionic liquid, 1-butyl-3- methylimidazolium hexafluorophosphate [bmim][PF6], and in a 1-butyl-3-methylimidazolium bromide ([bmim][Br]) - benzene system. The reactions with acrolein and crotonaldehyde afforded Michael addition products, those with citral resulted in Knoevenagel addition products. Sonication increased the yields of the Michael adducts. The ionic liquid [bmim][PF6] can be recovered and repeatedly used in the reactions.
- Kryshtal,Zhdankina,Astakhova,Zlotin
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p. 647 - 651
(2007/10/03)
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- Condensations of ethyl 3-ethoxy-4-(triphenylphosphoranylidene)-2-butenoate with α,β-unsaturated carbonyl compounds
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Wittig condensations of α,β-unsaturated carbonyl compounds with ethyl 3-ethoxy-4-(triphenylphosphoranylidene)-2-butenoate gave good to high yields of (2E,4E,6E)-ethyl 3-ethoxy-2,4,6-alkatrienoates. Some of last mentioned compounds were almost quatitativel
- Moorhoff, Cornelis M.
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- Synthesis of Saturated Anacardic Acids, and Alkenyl and Alkynyl Analogues
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The C-alkylation of esters of 2-methoxy-6-methylbenzoic acid and of the 4-methyl isomers affords a route to homologous compounds including in the former case members of the natural anacardic acids from Anacardium occidentale and ω-alkynyl compounds suitable for synthesising other natural phenolic lipids or for structure/activity studies.
- Tyman, John H. P.,Visani, Naina
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p. 228 - 240
(2007/10/03)
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- Efficient total synthesis of AI-77-B, a gastroprotective substance from Bacillus pumilus AI-77
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First total synthesis of AI-77-B (1), a gastroprotective substance from Bacillus pumilus AI-77, was achieved in a stereoselective and convergent manner. In this synthesis, the dihydroisocoumarin part 2 was constructed in one step through 1,2-addition of the benzylic anion 17b to Boc-L-leucinal 7b. The hydroxy amino acid 4 was elaborated from (R)-glutamic acid in a highly stereoselective manner. Condensation of 2·HCl and 4, intramolecular Pinner reaction, followed by mild hydrolysis afforded AI-77-B (1).
- Hamada,Hara,Kawai,Kohno,Shioiri
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p. 8635 - 8652
(2007/10/02)
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- LITHIUM IODIDE-CATALYZED CONJUGATE ADDITION OF β-DICARBONYL COMPOUNDS
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Lithium iodide proves to be a very efficient catalyst for Michael addition of β-dicarbonyl compounds.The successful application of this methodology to α,β-unsaturated aldehydes allows an improved approach to 5,6-disubstituted cyclohex-2-en-1-ones.
- Antonioletti, R.,Bonadies, F.,Monteagudo, E. S.,Scettri, A.
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p. 5373 - 5374
(2007/10/02)
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- SYNTHETIC STUDIES ON NOGALAMYCIN CONGENERS ; SYNTHESES AND ANTITUMOR ACTIVITY OF VARIOUS NOGALAMYCIN CONGENERS
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Various structural types of nogalamycin congeners and their partial structures, which had been previously synthesized in the course of our synthetic studies on the total syntheses or were originally produced by employing the explored synthetic scheme, were subjected to in vitro cytotoxicity and in vivo antitumor activity assay against P388 murine leukemia.These studies obviously disclosed novel aspects of the structure-activity relationships of nogalamycin congeners.
- Matsuda, Fuyuhiko,Kawasaki, Motoji,Ohsaki, Masako,Yamada, Kaoru,Terashima, Shiro
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p. 5745 - 5760
(2007/10/02)
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- CONDENSATION OF ETHYL AND METHYL 4-(TRIPHENYLPHOSPHORANYLIDENE)-3-OXOBUTANOATE WITH ENALS
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The manipulation of the mode of reaction of 4-(phosphoranylidene)-3-oxobutanoates with enals and a resulting new synthesis of ethyl β-safranate have been explored.
- Moorhoff, Cornelis M.,Schneider, David F.
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p. 4721 - 4724
(2007/10/02)
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