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121.
Dikusar E. A. Kozlov N. G. Moiseichuk K. L. 《Russian Journal of Organic Chemistry》2002,38(10):1440-1444
Reaction of butyllithium with acetylene and 1-hexyne gave the corresponding lithium acetylides which reacted with (-)-(R)- and (+)-(S-carvone in a stereospecific fashion to give lithium (1-ethynyl- or 1-hexynyl)-5-isopropenyl-2-methyl-2-cyclohexenolates. Hydrolysis of the latter gave individual optically active tertiary terpene alcohols having both acetylenic and p-menthene fragment. Their treatment with methyl iodide in the presence of hexamethylphosphoric triamide afforded the corresponding methyl ethers. The reaction of 3-ethynyl-5-isopropenyl-3-methoxy-2-methylcyclohexene with butyllithium and trichloro(vinyl)silane yielded optically active dichlorosilyl-containing acetylenic compounds. 相似文献
122.
123.
Ring cleavage in 4-methyl-5-phenyl-2,3-dihydrofuran-2,3-dione by the action of methanol and in 5-aryl-4-methyl-2,3-dihydrofuran-2,3-diones by the action of aniline and N-methylaniline results in formation of, respectively, methyl 3-methyl-4-phenyl-2,4-dioxobutanoate and 4-aryl-3-methyl-2,4-dioxobutananilides. The reaction mechanism was studied by 1H NMR spectroscopy. 相似文献
124.
Herbert Schumann Kerstin Zietzke Frank Erbstein Roman Weimann 《Journal of organometallic chemistry》1996,520(1-2):265-268
LnCl3 reacts with Na(C5Me41Bu) in THF to form the organolanthanoid chlorides [(C5Me41Bu)2LnCl(THF)] (Ln = La (1a), Lu (1b)). Compounds 1a and 1b yield in reaction with NaO2CCH3 the monomeric organolanthanoid acetates [(C5Me41Bu)2LnO2CCH3] (Ln = La (2a), Lu (2b)). The single crystal X-ray structure analysis of 2b as well as the cryoscopic molecular weight investigation of 2a verify the monomeric structure of these complexes. 相似文献
125.
S. S. Koval'skaya N. G. Kozlov M. G. Novikova S. V. Shavyrin 《Chemistry of Natural Compounds》1990,26(1):28-32
The transformations of 2a-hydroxy-2,6,6-trimethylbicyclo[3.1.1]heptan-3-one under the conditions of acid catalysis have been studied. It has been shown that this compound can be used for the synthesis of products of various structures: a bridged bicyclic lactone (1,8,8-trimethyl-2-oxabicyclo[3.2.1]octan-3-one), an aromatic compound (carvacrol), and nitrogen-containing derivatives of p-menthane such as 8-acylamino-p-menth-6-en-2-ones. The structures of the compounds synthesized were shown by the results of1H and13C NMR spectroscopies.Institute of Physical Organic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 35–42, January–February, 1990. 相似文献
126.
1,3-Cyclopentanedione bis(4-methylthiosemicarbazone) monohydrochloride produces colored solutions with chlorate ions in strongly acid medium. The yellow color obtained has been used to propose a spectrophotometric method of C103? determination in the concentration range 0.5–6.0 ppm (molar absorptivity 1.26 × 104 liters mol?1 cm?1 at a wavelength of 397 nm). 相似文献
127.
Philip M. Carabateas R. Pauline Brundage Karl O. Gelotte Monte D. Gruett Roman R. Lorenz Chester J. Opalka Jr. Baldev Singh William H. Thielking Gordon L. Williams George Y. Lesher 《Journal of heterocyclic chemistry》1984,21(6):1849-1856
A series of substituted 3- and 4-(3-aminophenyl)pyridines has been prepared as intermediates for the synthesis of some 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids. The Hantzsch, Hauser and other pyridine syntheses were used. 4-(3-Aminophenyl)pyridine was prepared via 3-(4-pyridinyl)-2-cyclohexen-1-one using the Semmler-Wolff reaction. 相似文献
128.
The paper is one of a cycle of numerical investigations of two-dimensional flows of plasma in the channel of a plasma accelerator. The channel is formed by two coaxial electrodes. The current between them generates an azimuthal magnetic field, and the interaction of the current with the field leads to acceleration of the plasma. The flow is calculated on the basis of the two-dimensional axisymmetric non-stationary magnetohydrodynamic equations [1]. Attention is concentrated on the process of ionization of the gas in the channel, this being simulated by a discontinuous dependence of the conductivity on the temperature: Rem = 0 for T < T* and 1 + 2· T3/2 for m T*.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 183–185, March–April, 1983.I thank the initiators of this present investigation, K. V. Brushlinskii and A. I. Morozov, for constant interest in the work. 相似文献
129.
Koval'skaya S. S. Kozlov N. G. Dikusar E. A. 《Russian Journal of Organic Chemistry》2002,38(8):1116-1124
By treating 2e-methyl-4-oxo-trans-decahydroquinoline with lithium acetylide a mixture of stereoisomeric 4-cis-hydroxy-2e-methyl- and 4-trans-hydroxy-2e-methyl-4-ethynyl-trans-decahydroquinolines was obtained in 3:2 ratio. Their reaction with acetonitrile in the presence of sulfuric acid (Ritter's reaction) results in a mixture of stereoisomeric 4-cis-acetylamino-2e-methyl- and 4-trans-acetylamino-2e-methyl-4-ethynyl-trans-decahydroquinolines in the same ratio. The ethynyl group of alcohols synthesized is not hydrated under conditions of Kuchrerov's reaction. The boiling of the alcohols with formic acid furnished a mixture of 4-acetyl-2e-methyl and 2e-methyl-4-ethynyl-1,2,3,6,7,8,9,10-octahydroquinolines in 1:7 ratio. The former of these compounds under conditions of Ritter's reaction yielded a mixture (1:1.4) of stereoisomeric 4-acetyl-4-trans-acetylamino- and 4-acetyl-4-cis-acetylamino-2e-methyl-trans-decahydroquinolines. From 2e-methyl-4-ethynyl-1,2,3,6,7,8,9,10-octahydroquinoline under the same conditions were obtained both already mentioned stereoisomeric 4-acetylamino-2e-methyl-4-ethynyl-decahydroquinolines (53% of cis-isomer and 35% of trans-isomer in the mixture) and 4-acetyl-4-acetylamino-2e-methyldecahydroquinolines (7% of cis-isomer and 5% of trans-isomer). 相似文献
130.
Kaupp M Patrakov A Reviakine R Malkina OL 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(9):2773-2782
The characteristic dependence of J(31P,31P) spin-spin coupling constants of alkali metal tetraphosphane-1,4-diides on structure and composition has been analyzed by density functional methods. The computations confirm that the structure of the contact ion pairs is conserved in solution. Calculations on model systems M2P4H4, on naked P4H4(2-) anions, and on models including point charges, show that the role of the cations is mainly structural and to a smaller extent electrostatic. Three of the four J(P,P) coupling constants depend characteristically on the conformation of the anion, which in turn is determined by the substituents R and by cation-anion interactions. Several couplings exhibit a large through-space component and are thus strongly dependent on the relative orientation of nonbonding electron pairs on the phosphorus atoms involved. This is shown by visualization of coupling pathways using the recently introduced coupling energy density (CED), in combination with the electron localization function (ELF). 相似文献