- Natural products inspired synthesis of neuroprotective agents against H2O2-induced cell death
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Stroke is a debilitating disease and the third leading cause of death in the USA, where over 2000 new stroke cases are diagnosed every day. Treatment options for stroke-related brain damage are very limited and there is an urgent need for effective neurop
- Almaliti, Jehad,Nada, Shadia E.,Carter, Bryaune,Shah, Zahoor A.,Tillekeratne, L.M. Viranga
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supporting information
p. 1232 - 1237
(2013/03/14)
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- A Novel Hetero-Diels-Alder Approach towards Perhydro Quinolinones Bearing an Angular Methyl Group
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The title compounds 9-11 were synthesized by a hetero Diels-Alder reaction using the sterically demanding diene 2 as a new building block. The effect of commonly used Lewis acids and the substitution pattern of various imines 5 on both the mechanism and t
- Stanetty, Peter,Mihovilovic, Marko D.,Mereiter, Kurt,Voellenkle, Horst,Renz, Franz
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p. 875 - 894
(2007/10/03)
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- Use of a Sacrificial Aluminum Anode in the Acylation of Some Olefins
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The acylation of some alicyclic and aliphatic alkenes by the electrochemical generation of a catalyst using a sacrificial aluminum anode was investigated. Substrates were electrolyzed in a dichloromethane solution of an appropriate electrolyte (tetraalkylammonium salts) in the presence of an acylating agent (acetyl chloride or anhydride). Thus, unsubstituted cycloalkenes, namely cyclohexene and cycloheptene, gave by that reaction conjugated ketones, i.e. the corresponding 1-acetylcycloalkenes, as the only unsaturated carbonyl compounds in moderate-to-good yields. Under the same reaction conditions their 1-methyl derivatives gave mixtures of the corresponding conjugated and β,γ-unsaturated isomeric ketones in which unconjugated compounds predominate. In both cases unsaturated ketones were accompanied by different amounts of side products. Terminal aliphatic alkenes (1-hexene, 1-heptene, and 1-dodecene) afforded only conjugated a ketone with a normal skeleton, but in lower yields. The acylation of cyclohexene was studied in more detail, altering the reaction conditions by changing the reaction temperature, the supporting electrolyte, the acylating agent and the electrochemical cell. Mechanistic considerations were made on the basis of the products distribution and some theoretical calculations being made by the MOPAC program package (version 7.0).
- Vukicevic, Rastko D.,Joksovic, Ljubinka,Konstantinovic, Stanimir,Markovic, Zoran,Mihailovic, Mihailo Lj.
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p. 899 - 904
(2007/10/03)
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- Phosphane Alkylenes, 53. - Synthesis of α,β-Unsaturated Cycloalkanones from Bis - A Method for the Transformation of Acid Anhydrides into Carbocyclic and Heterocyclic Compounds
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Alkaline hydrolysis of bis 3 leads to 2-cycloalken-1-ones 6.Intramolecular Wittig reaction of an intermediately formed monoacyl ylide 4 and intramolecular aldol condensation of a diketone 5, resulting from hydrolysis of both ylide functions, are discussed as possible reaction mechanisms.The oxidation of 3 with H2O2 * Ph3PO yields 7- and 8-membered 2-cycloalkene-1,4-diones 12, presumely via mono ylides 11 carrying an aldehyde group in the ω-position.The reactions of 3 with aldehydes (molar ratio 1:1) lead to the formation of mono Wittig compounds 15 which can cyclize affording 5- and 6-membered 3-alkenyl-2-cycloalken-1-ones 16.Since the ylides 3 are easily available from acid anhydrides the reaction sequences represent versatile approaches for the transformation of acid anhydrides into 2-cycloalken-1-ones. Key Words: Phosphonium ylides / Wittig reactions, intramolecular / Aldol condensations, intramolecular / 2-Cycloalken-1-ones / 2-Cycloalken-1,4-diones
- Bestmann, Hans Juergen,Pichl, Rainer,Zimmermann, Reiner
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p. 725 - 732
(2007/10/02)
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- Chromium(II) Reduction of Trichloromethyl Carbinols and their Corresponding Ethers: One-step Synthesis of Z-Vinyl Chlorides
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Secondary trichloromethyl carbinols and their corresponding ethers can be reduced by chemically or electrochemically generated chromium(II) chloride to form Z-monochlorovinyl compounds in one step.In the presence of a carboxy function in the α-position an E-double bond is formed.Tertiary cabinols favour the formation of dichlorovinyl compounds and rearranged carbonyl compounds.Product ratios can be altered drastically by a change in the reaction conditions; this sheds light on the reaction mechanism.
- Wolf, Reinhard,Steckhan, Eberhard
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p. 733 - 740
(2007/10/02)
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- ALUMINUM OXIDE CATALYZED ISOMERIZATION OF ACYLATED CYCLOALKENES
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A homologous series of cyclic olefins and their corresponding 1-methyl derivatives were acylated using acetic anhydride/zinc chloride system.The resulting mixtures were, after appropriate analysis, isomerized quantitatively to the conjugated enones by adsorption on neutral alumina.A detailed, general experimental procedure is given.
- Hudlicky, T.,Srnak, T.
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p. 3351 - 3354
(2007/10/02)
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