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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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A stereospecific, highly efficient, generally applicable synthesis of Z- and E-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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The enantiomeric alcohols (2) and (11), obtained from (2R,3R) tartaric acid and, respectively, L-threonine, have been used to construct the C6, enantiomeric deoxy amino sugar derivatives (7) and (12)  相似文献   

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The 1H and 13C nmr spectra of exo, exo-9-oxobicyclo[3.3.1]nonane-2,4-dicarboxylic acid, 3, in DMSO-d6 or alkaline D2O, clearly show that it exists in a boat-chair-conformation with equatorial carboxyl groups, thus being the first case of boat-chair preference of a bicyclo[3.3.1] nonan-9-one due to the presence of exo,exo-2,4- substituents.  相似文献   

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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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In strong base, e.g., sodium hydride in dimethylformamide, N-(o-azidobenzoyl)arylamines cyclise in high yield to 2-aryl-1,2-dihydro-3H-indazolin-3-ones.  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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Although the hydrochloride of c-4-t-butyl-1-phenyl-c-1-(N-piperidyl)cyclohexane crystallizes in the conformation with axial t-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°t-Bu as ?4.9 kcal/mol.  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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