共查询到20条相似文献,搜索用时 15 毫秒
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J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of and [2+2]cycloadducts of benzyne to , - and , -1,5-cyclooctadiene, - and -cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described. 相似文献
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Although the hydrochloride of -4--butyl-1-phenyl--1-(N-piperidyl)cyclohexane crystallizes in the conformation with axial -butyl, it exists as an almost equimolar mixture of the two chair conformers in CD2 Cl2 solution. The position of equilibrium allows one to calculate ΔG°-Bu as ?4.9 kcal/mol. 相似文献
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A stereospecific route to -2,2-dimethyl-3-alkenyl-cyclopropanecarboxylic Acids is illustrated by a total synthesis of (±)--Chrysanthemic Acid (11). The key step consists of an alicyclic Claisen rearrangement of -silyl enolates derived from appropriately substituted ()-4-hexen-6-olides [e.g.(9)]. 相似文献
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Non enzymatic hydration of leukotriene A (), the biogenetic precursor of leukotriene B () affords among other products two diastereomeric 6--isomers of 2, the first stereospecific and efficient syntheses of which are recorded herein. 相似文献
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Complexes of the type L2PdCl2 (L = CH3,CN, CH3CH2CN, PhCN) in benzene or chloroform act as homogeneous catalysts in the room temperature to isomerization of ethylchrysanthemate and chrysanthemic acid. 相似文献
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A stereospecific, highly efficient, generally applicable synthesis of - and -1-alkoxy-1,3-butadienes involving dehydrative decarboxylations of 4,5-unsaturated-2-alkoxy-3-hydroxy-carboxylic acids is described. 相似文献
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M.Gary Newton Nantelle Pantaleo Wesley G. Bentrude S. Chandrasekaran 《Tetrahedron letters》1982,23(15):1527-1530
An X-ray crystallographic study of the title compound shows it to have an axial Me2N with pyramidal N and a lengthened N-P bond. Conversely, the endocyclic NH-P bond is shortened. The origins of these effects are assigned to specific geometrical relationships of the Me2N/P=S and NH/P=S groupings imposed by the ring system. 相似文献
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The 6-hydroperoxy-1,4-cyclooctadiene (), which is formed in the photosensitized oxygenation of 1,5-cyclooctadiene (), affords on further singlet oxygenation 5,8-dihydroperoxy-1,3-cyclooctadiene (), which via triphenylphosphine reduction leads to -5,8-dihydroxy-1,3-cyclooctadiene () and subsequent pyridinium chlorochromate oxidation to 1,3-cyclooctadien-5,8-dione (). 相似文献
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Tadashi Nakata Shigeto Nagao Sachiko Takao Tadasu Tanaka Takeshi Oishi 《Tetrahedron letters》1985,26(1):73-74
(1,3,5)-1,3-Dimethyl]-2,9-dioxabicyclo[3.3.1]nonane has been stereoselectively synthesized based on a highly stereoselective method for the synthesis of 1,3--polyol. 相似文献
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The nitration of -cresol by nitric acid in aqueous sulphuric acid involves ~40% -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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