共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Madesclaire V. P. Zaitsev J. V. Zaitseva S. Kh. Sharipova 《Chemistry of Heterocyclic Compounds》2007,43(10):1325-1332
A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds
was studied.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007. 相似文献
2.
M. I. Mallyabaeva A. Yu. Spivak T. V. Tyumkina O. V. Knyshenko V. N. Odinokov 《Russian Chemical Bulletin》2007,56(12):2443-2447
Short and efficient synthesis of (3R,7R)-hexahydrofarnesyl bromide ((3R,7R)-1-bromo-3,7,11-trimethyldodecane), the terpenoid synthon for the natural α-tocopherol, has been elaborated based on the
microwave-activated regioselective enolization of homochiral phytone.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2360–2363, December, 2007. 相似文献
3.
A new compound (5R, 10R)-3,8-dihydroxy-5,10-diethoxy-5,10-dihydrochromeno[5,4,3-cde]chromene monohydrate was obtained from 3,4-dihydroxybenzaldehyde in aerobic basic aqueous ethanol solution in the presence
of manganese chloride and triethylamine and crystallized in orthorhombic P212121 space group (denoted as 1). When 1 was recrystallized from aqueous methanol, it was transformed to another crystal (2) with the same composition but in P21/n space group. The drastic difference in the extensive hydrogen bond network makes 1 a 3D and 2 a 2D infinite supramolecular structure, respectively. 相似文献
4.
G. Yu. Ishmuratov M. P. Yakovleva G. V. Zaripova L. P. Botsman R. R. Muslukhov G. A. Tolstikov 《Chemistry of Natural Compounds》2004,40(6):548-551
A novel synthesis of the promising optically pure chiral (4R)-4-methylpentanolide that is based on several regiospecific oxidative transformations of (4R)-2,4-dimethyl-1-(1-methylethyl)-1-cyclohexene, the product of addition of (–)-menthone and methylmagnesium iodide followed by acid dehydration, was proposed.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 451–453, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
5.
Krisztián Bogár 《Central European Journal of Chemistry》2005,3(1):63-71
(R, R)-(−)-N, N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminocobalt(II) was encapsulated into MCM-22 using the zeolite synthesis method. The
encapsulated catalyst proved to be active in the oxidation of α-methylstyrene with NaOCl with higher specific activity than
the homogeneous catalyst. At the same time, this encapsulated catalyst was completely inactive in the hydrolytic kinetic resolution
of racemic styrene oxide. This observation is in a good correlation with the assumption of the cooperative bimetallic mechanism
proposed by Annis and Jacobsen. 相似文献
6.
J. A. Jilani 《Chemical Papers》2007,61(5):410-412
8-Amino-1-methoxy-6H-dibenzo[b,d]pyran-6-one was synthesized in a one-pot reaction of 2′,6′-dimethoxy-4-nitro-1,1′-biphenyl-2-carboxylic acid methyl ester
using hydroiodic acid as a reagent to effect O-demethylation, lactonization, and nitro reduction to amine. This new reaction represents an improved alternative to the previously
reported three-step reactions for this transformation. 相似文献
7.
V. Ya. Sosnovskikh M. A. Barabanov B. I. Usachev R. A. Irgashev V. S. Moshkin 《Russian Chemical Bulletin》2005,54(12):2846-2850
Condensation of 4-acetyl-5-hydroxy-3-methyl-1-phenylpyrazole with RFCO2Et (RF = CF2H, CF3) in the presence of LiH affords 4-di(tri)fluoroacetoacetyl-5-hydroxy-3-methyl-1-phenylpyrazoles from which 6-di(tri)fluoromethyl-and
5-di(tri)fluoroacetyl-3-methyl-1-phenylpyrano[2,3-c]pyrazol-4(1H)-ones were synthesized. The reactions of pyrano-pyrazoles with hydrazine hydrate, ethyl mercaptoacetate, or aromatic amines
proceed at the C(6) atom with pyrone ring opening and formation of aminoenones, pyrazoles, or thiophenes with the 5-hydroxy-3-methyl-1-phenyl-4-pyrazolyl
fragment.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2750–2754, December, 2005. 相似文献
8.
A. I. Krivoshey N. S. Pivnenko S. V. Shishkina A. V. Turov L. A. Kutulya O. V. Shishkin 《Russian Chemical Bulletin》2006,55(6):999-1009
The spatial structure of (Z)-(5R)-methyl-2-(4-phenylbenzylidene)cyclohexanone prepared by photochemical isomerization of the E-isomer was studied by analyzing the magnitudes and temperature dependence of the proton spin-spin coupling constants obtained
by 1H NMR spectroscopy and the results of molecular modeling using semiempirical quantum chemical AM1 and PM3 methods and the
density functional theory (DFT). Comparison of the results obtained for the Z-and E-isomers shows that in both cases the conformational equilibrium for both isomers is characterized by significant preference
of the chair conformer having an equatorial methyl group, namely, − ΔH (chair a ⇌ chair e) = 1.98–2.12 and 1.36–1.54 kcal mole−1 for the Z-and E-isomers, respectively. Distinctions in the non-planarity of the enone fragment and cyclohexanone ring in the Z-and E-isomers under study following from the results of mathematical modeling were confirmed by the experimental values of the
geminal spin-spin coupling constants of protons of the methylene groups in α,α ′-positions with respect to the enone group.
Quantum chemical calculations of the Z-isomer revealed the existence of intramolecular hydrogen bond between the carbonyl oxygen and the nearest aromatic proton
in ortho-position of the benzene ring. Possible reasons for different helical twisting power of (Z)-(5R)-methyl-2-(4-phenylbenzylidene)cyclohexanone and the E-and Z-arylidene derivatives of 1R, 4R-isomenthone in the mesophase are discussed based on the results of molecular structure studies for these compounds.
In the text below the unsaturated ketones under study will be called “arylidene cyclohexanone derivatives” for convenience
of comparing the characteristics of methylcyclohexanone and isomenthone derivatives.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 962–972, June, 2006. 相似文献
9.
I. M. Chung H. Y. Park S. C. Chun J. J. Kim A. Ahmad 《Chemistry of Natural Compounds》2007,43(4):417-421
Three new compounds, 4-hydroxymethylene-7-(9,9,13-trimethylcyclohexyl)-heptanyl-3′,7′,7′-trimethylcyclohexa-2′,4′-dien-1′-oate
(1), 1-(n-hexadec-7-enoxy)-6-(n-octadecanoxy)-β-D-glucopyranoside (2), and (Z)-12-hydroxy-9-octadecenoic acid-12-β-D-glucopyranoside (3), along with the known compound hexacosanoic acid (4), were isolated and identified from the rice hulls of Oryza sativa. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques (1H-1H COSY, 1H-13C HETCOR, DEPT) aided by EIMS, FABMS, HRFABMS, and IR spectra.
Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 344–347, July–August, 2007. 相似文献
10.
I. I. Ponomarev D. Yu. Razorenov D. S. Perekalin P. V. Petrovskii Z. A. Starikova 《Russian Chemical Bulletin》2007,56(1):154-159
The reaction of 2-methyl-3-(4-tolyl)-4(3H)-quinazolone with benzil produces 2-[(Z)-3-oxo-2,3-diphenylprop-1-enyl]-3-(4-tolyl)-4(3H)-quinazolone, which is readily transformed into 2-(3,3-diphenylsuccinimido)-N-(4-tolyl)benzamide on dissolution in organic water-containing solvents. The rearrangement mechanism was suggested and investigated
by the quantum chemical PM3 method.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 146–151, January, 2007. 相似文献
11.
A new synthetic approach to 4E,7Z-tridecadien-1-ylacetate, a component of the Phthorimaea opercucella (Zeller) potato moth sex pheromone, was developed using a highly stereoselective Claisen rearrangement and Wittig reaction.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 235–236, May–June, 2007. 相似文献
12.
A. A. Kicha N. V. Ivanchina A. I. Kalinovsky P. S. Dmitrenok V. A. Stonik 《Russian Chemical Bulletin》2005,54(5):1266-1271
A fraction of sulfated polyhydroxylated steroids from the Far-Eastern starfish Ctenodiscus crispatus was investigated. The main component of this fraction was identified as (22E,24R,25R)-24-methyl-5α -cholest-22-en-3β,5,6β,15α,25,26-hexol 26-O-sulfate. For the compound stereoisomeric with respect to the side chain, the (24R,25S) or (24S,25R) relative configurations were assigned to the C(24) and C(25) chiral centers. The structures of two other compounds isolated
from the fraction were identified as (22E, 24ξ)-26,27-bisnor-24-methyl-5α-cholest-22-en-3β,5,6β,15α,25-pentol 25-O-sulfate and (22E, 24ξ,25ξ)-24-methyl-5α-cholest-22-en-3β,5,6β,8,15α,25,26-heptol 26-O-sulfate.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
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Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1229–1234, May, 2005. 相似文献
13.
I. V. Nechepurenko M. P. Polovinka N. I. Komarova D. V. Korchagina N. F. Salakhutdinov S. B. Nechepurenko 《Chemistry of Natural Compounds》2008,44(1):31-34
Isoflavonoids (−)-medicarpin, (−)-vestitol, formononetin, 8-hydroxydaidzein, and 6″-O-acetylononin were isolated for the first time in addition to (−)-catechin, (−)-epicatechin, protocatechoic acid, raspberry
ketone, and rhododendrol from the alcohol extract of Hedysarum theinum roots.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 26–28, January–February, 2008. 相似文献
14.
K. A. Frolov V. V. Dotsenko S. G. Krivokolysko A. N. Chernega V. P. Litvinov 《Russian Chemical Bulletin》2005,54(5):1340-1342
Reduction of (E)-3-aryl-2-(4-arylthiazol-2-yl)acrylonitriles with lithium aluminum hydride in dry ether afforded (Z)-1-amino-3-aryl-2-(thiazol-2-yl)prop-1-ene derivatives in 15 to 40% yields. The structure of (Z)-1-amino-3-(2-chlorophenyl)-2-[4-(4-methylphenyl)thiazol-2-yl]prop-1-ene was confirmed by X-ray diffraction analysis.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
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Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1301–1303, May, 2005. 相似文献
15.
T. G. Drushlyak L. A. Kutulya N. S. Pivnenko V. V. Vashchenko 《Russian Journal of General Chemistry》2005,75(4):622-627
Carbonylation of (E)-2-(4-halobenzylidene)-p-menthan-3-ones, catalyzed by PdCl2(PPh3)2, gave a distereometric mixure of 4-[(1R,4R)- and (1R,4S)-3-oxo-p-menthan-2-ylidenemethyl]benzoic acids, whose reaction with phenols gave 1R,4R diastereomers of the corresponding esters.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 659–664.Original Russian Text Copyright © 2005 by Drushlyak, Kutulya, Pivnenko, Vashchenko. 相似文献
16.
Nickel acetate promoted reaction of diethyl acetone-1,3-dicarboxylate with N-cyanobenzamidine led to ethyl 4-amino-6-ethoxycarbonylmethyl-2-phenylpyrimidine-5-carboxylate, upon treatment of which with
RNH2, the corresponding 6-(carbamoylmethyl)pyrimidines were obtained. Cyclization of the latter upon treatment with MeONa afforded
6-R-4-amino-7-hydroxy-2-phenylpyrido[4,3-d]pyrimidin-5(6H)-ones.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2212–2214, November, 2007. 相似文献
17.
Microorganisms producing lipase were isolated from soil and sewage samples and screened for enantioselective resolution of
(R,S)-methyl mandelate to (R)-mandelic acid. A strain designated as GXU56 was obtained and identified as Burkholderia sp. Preparing immobilized GXU56 lipase by simple adsorption on octyl sepharose CL-4B, the optimum temperature was shifted
from 40 °C (free lipase) to 50 °C (immobilized lipase), and the optimum pH was shifted from 8.0 (free lipase) to 7.2 (immobilized
lipase). The immobilized enzyme displayed excellent stability in the pH range of 5.0–8.0, at the temperatures below 50 °C
and in organic solvents compared with free enzyme. Enantioselectivity ratio for (R)-mandelic acid (E) was dramatically improved from 29.2 to more than 300 by applying immobilized lipase in the resolution of (R,S)-methyl mandelate. After five cycles of use of immobilized lipase, conversion and enantiomeric excess of (R)-mandelic acid were 34.5% and 98.5%, respectively, with enantioselectivity ratio for (R)-mandelic acid (E) of 230. Thus, octyl-sepharose-immobilized GXU56 lipase can be used as a bio-resolution reagent for producing (R)-mandelic acid. 相似文献
18.
Xiu-Kui Qu Lan-Ying Zhu Ling Li Xi-Lian Wei Feng Liu De-Zhi Sun 《Journal of solution chemistry》2007,36(5):643-650
As a continuation of our previous investigation, interactions between cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and alkyl trimethylammonium bromides in aqueous solutions have been studied with titration calorimetry and 1H NMR at 298.15 K. The results are discussed in terms of the amphiphilic interaction of CD with surfactants and the iceberg
structure formed by water molecules existing around the hydrophobic tail of surfactant molecules. The stoichiometry of the β-CD–surfactant system is 1:1 whereas that of the γ-CD–surfactant system is 1:2. The corresponding formation enthalpy (negative) of the complexes of the two systems decreases
with an increase in the number of carbon atoms (n) in hydrophobic chain of surfactant molecule, C
n
H2n+1, whereas the entropy increases with the enlargement of n. 相似文献
19.
S. N. Senchenkova A. S. Shashkov Yu. A. Knirel M. Ahmed A. Mavridis K. Rudolph 《Russian Chemical Bulletin》2005,54(5):1276-1281
An O-polysaccharide was prepared by mild acid hydrolysis of a lipopolysaccharide of Erwinia carotovora ssp. atroseptica GSPB 9205 and was found to contain a new higher branched monosaccharide, viz., 3,6,8-trideoxy-4-C-(R-1-hydroxyethyl)-D-gulo-octose, which we called erwiniose. The structure of the pentasaccharide repeating unit of the O-polysaccharide was established
by monosaccharide analysis, including the determination of absolute configurations, methylation analysis, O-deacetylation, Smith degradation, and one- and two-dimensional NMR spectroscopy. The configuration of erwiniose was determined
based on the coupling constants of vicinal protons combined with the nuclear Overhauser effect data and the results of periodate
oxidation of the polysaccharide followed by reduction of the resultant 4-keto sugar (the C(1)-C(4)-C(1′)-C(2′) fragment) to
give 3,6-dideoxy-D-ribo-hexose(paratose) and oxidation of 3-hydroxybutyraldehyde (the C(5)-C(8) fragment) to give R-3-hydroxybutyric acid.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
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Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1239–1244, May, 2005. 相似文献
20.
D. V. Shishkin E. R. Mukhamed’yarova N. Z. Baibulatova V. A. Dokichev Yu. V. Tomilov 《Chemistry of Natural Compounds》2007,43(3):293-297
Diastereomers of N-(2-(1-adamantyl)-2-hydroxyethyl)cytisine were synthesized by reduction of N-(2-(1-adamantyl)-2-oxoethyl)cytisine with NaBH4. Their structures were established using x-ray structure analysis.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 244–247, May–June, 2007. 相似文献