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All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled.  相似文献   

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The instrument described is suitable for the investigation of the thermal behaviour of substances and reaction mixtures under production conformable conditions; this is made possible by the sophisticated design of the sample chamber: easy stirring of the samples, measuring under any gas atmosphere and while bubbling gas through the sample, choice of the sample container and visual observation during the measurement. The control device allows the choice of one of three operational modes: constant temperature, linear increase in temperature, and adiabatic control; this permits the application of the SEDEX apparatus for a variety of methods including dynamic scanning, isoperibolic measurements, and (quasi) adiabatic studies.  相似文献   

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By appropriate choice of reaction conditions, the same enantiomerically pure (S)-(+)-2-(p-tolylsulfinyl)cycloalkenone can be converted into either an (R)-or an (S)-3-substituted cycloalkanone in good to excellent enantiomeric purity.  相似文献   

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3H-Indazol-3-one has been generated by thermolysis of N(o-azidobenzoyl)iminopyridinium ylide and trapped as its Diels-Alder cycloadducts with several dienes.  相似文献   

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Palladium catalysed alkoxycarbonylation of heterocyclic halides affords a simple and versatile synthesis of both N and S heterocyclic esters where a range of catalysts have been studied and a method to employ inexpensive inorganic bases has been found.  相似文献   

11.
J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of cis and trans [2+2]cycloadducts of benzyne to cis, trans- and cis, cis-1,5-cyclooctadiene, trans- and cis-cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described.  相似文献   

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The term MIRC reaction is defined. Examples of the construction of three, five, six and seven membered rings using alkylthiolates and LDA as nucleophiles are presented.  相似文献   

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We describe a short synthesis of (S)-5-hydroxymethyl-(5H-furan-2-one and some 5-O-derivatives, which are being used as key starting products for the synthesis of several antileukaemic lignan lactones, from D-ribonolactone.  相似文献   

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Pinacol E-1-trimethylsilyl-1-propene-3-boronate reacts with aldehydes to form (±)-(R*,S*)-3-trimethylsilyl-4-hydroxy-1-alkenes, which can be deoxysilylated stereoselectively to either 98% Z or 99% E 1,3-dienes, including the separate components of the red bollworm moth pheromone.  相似文献   

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The nitration of p-cresol by nitric acid in aqueous sulphuric acid involves ~40% ipso-substitution at CMe. The 4-methyl-4-nitrocyclohexa-2,5-dien-1-one (I) formed undergoes an acid-catalysed rearrangement to 4-methyl-2-nitrophenol.  相似文献   

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Non enzymatic hydration of leukotriene A (1), the biogenetic precursor of leukotriene B (2) affords among other products two diastereomeric 6-trans-isomers of 2, the first stereospecific and efficient syntheses of which are recorded herein.  相似文献   

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