共查询到20条相似文献,搜索用时 546 毫秒
1.
E. N. Adamenko L. L. Frolova M. V. Panteleeva A. V. Kuchin 《Chemistry of Natural Compounds》2007,43(1):59-62
Optically active camphordihydro-2,3-pyrazine and camphorquinoxaline were prepared from camphoroquinone enantiomers. It was
shown that (1S,4R)-(+)-camphoroquinone was formed by oxidation of (1S,3R, 4R)-(−)-3-bromocamphor and (1R,4S)-(−)-camphoroquinone from (1R,3S, 4S)-(+)-3-bromocamphor, respectively. Camphor anhydride was a side product (6–10%) of the reaction.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 50–52, January–February, 2007. 相似文献
2.
M. M. Mirzaeva B. Tashkhodzhaev M. G. Levkovich A. G. Eshimbetov P. Kh. Yuldashev N. D. Abdullaev 《Chemistry of Natural Compounds》2012,48(1):91-94
Transformation products of the alkaloid (–)-norfluorocurarine with hydroxylamine were studied. The oxime of norfluorocurarine
was obtained and converted by treatment with EtOH into 2-hydroxy-16-cyano-2,16dihydronorfluorocurarine. The structures of
2-hydroxy-16-cyano-2,16-dihydronorfluorocurarine and 16-cyanonorfluorocurarine hydrochloride were established by XSA and NMR
spectroscopy. The absolute structure of 2-hydroxy-16-cyano-2,16-dihydronorfluorocurarine was established and enabled the configurations
of the asymmetric centers to be determined as 2R, 3S, 7R, 15S, and 16R. 相似文献
3.
Two new lignans were isolated with two other known compounds, eusiderin A and eusiderin I, from Eusideroxylon zwageri (billian). The two new lignans have isomeric structure. The structures of the new lignans were determined to be (2R,3R,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy (3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin and (2R,3S,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy(3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin.
Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 303–305, May–June, 2009. 相似文献
4.
A. V. Tarantin V. A. Glushkov K. Yu. Suponitskii A. A. Kudryashov O. A. Maiorova A. G. Tolstikov 《Russian Journal of Organic Chemistry》2010,46(10):1479-1489
Glyoxylate and arylglyoxal imines based on 12-aminodehydroabietic acid undergo hetero-Diels—Alder (Povarov) reaction with
ethyl vinyl ether, cyclopentadiene, and indene to give, respectively, methyl (8aR,9R,12aS)-3-aroyl-5-isopropyl–9,12a-dimethyl–7,8,8a,9,10,11,12,12a-octahydronaphtho[1,2-f]quinoline-9-carboxylates, methyl (7R,10aS,10dR,13aS)-1-aroyl–3-isopropyl–7,10a-dimethyl–2,5,6,6a,7,8,9,10,10a,10d,13,13a-dodecahydro-1H-naphtho[1,2-f]cyclopenta[c]quinoline-7-carboxylates, and methyl (6aS,11bS,11eS,15R,15aR)-6-aroyl–4-isopropyl–11e,15-dimethyl–2,5,6,6a,7,11b,11e,12,13,14,15,15a-1H-dodecahydroindeno[2,1-c]-naphtho[1,2-f]quinoline-15-carboxylates. 相似文献
5.
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
6.
M. D. Alaniya N. F. Chkadua T. I. Gigoshvili E. P. Kemertelidze 《Chemistry of Natural Compounds》2006,42(4):445-448
The new cycloartane glycoside cycloascauloside A with the structure 20S,24R-epoxycycloartan-3β, 6α,16β,25-tetraol 3-O-[α-L-rhamnopyranosyl(1→6)]-β-D-(2′-O-acetyl)-glucopyranoside was isolated from leaves of Astragalus caucasicus Pall. The structure was established based on IR, PMR, and 13C NMR spectra and physicochemical properties of the compound itself and the products of its chemical transformations.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 359–361, July–August, 2006. 相似文献
7.
The new cycloartane glycoside cyclogaleginoside D, which has the structure 25-O-β-D-glucopyranoside-20S, 25R-epoxycycloartan-3β, 6α, 16β, 25-tetraol 3-O-β-D-(2-O-acetyl)xylopyranoside was isolated from Astragalus galagiformis stems. The structure of the glycoside was established using chemical transformations and IR, PMR, and 13C NMR spectral data.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 255–256, May–June, 2006. 相似文献
8.
P. Kh. Yuldashev B. Tashkhodzhaev K. K. Turgunov M. M. Mirzaeva 《Chemistry of Natural Compounds》2011,46(6):924-928
The bisindole compound 2β,16α,2′β,16′β(H)-tetrahydronordihydrotoxiferine consisting of two diastereoisomeric deoxytetrahydronorfluorocurarine moieties was isolated
from the reduction mixture of the alkaloid norfluorocurarine. 16-Deformyl-2,16,17,20-tetrahydro-20,21-dehydronorfluorocurarine
was produced by dehydrogenation of norfluorocurarine; N(β)-methyldihydrodefluorocurarine, by hydrogenation of fluorocurarine. The structures of the synthesized compounds were established
by x-ray structure analyses. The configurations of the asymmetric centers in 2β,16α,2′β,16′β(H)-tetrahydronordihydrotoxiferine were determined as 2S,3S,7R,15S,16R,2′S,3′S,7′R,15′S,16′S. Inversion to the R-configuration at the C15 center was observed in N(β)-methyldihydrodefluorocurarine whereas the configurations 3S and 7R were retained. Atom C2 adopted the S-configuration in 16-deformyl-2,16,17,20-tetrahydro-20,21-dehydronorfluorocurarine. 相似文献
9.
O. S. Kukovinets T. I. Zvereva V. G. Kasradze F. Z. Galin L. L. Frolova A. V. Kuchin L. V. Spirikhin M. I. Abdullin 《Chemistry of Natural Compounds》2006,42(2):216-218
An effective method was proposed for synthesizing (+)-cis-1R-acetoxymethyl-3-isopropenyl-2,2-dimethylcyclobutane, a pheromone of the citrus mealybug, based on ozonolysis of verbenone
that led in one step to the key synthon 1R,3S-3-acetyl-2,2-dimethylcyclobutanecarboxylic acid.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 179–180, March–April, 2006. 相似文献
10.
A new bicyclo[3.2.1]octanoid neolignan rel-(7S,8R,1′S,2′R,3′S)-Δ8′-2′-hydroxy-5,1′,3′-trimethoxy-3,4methylenedioxy-7,3′,8,1′-neolignan (1) was isolated from ethanol extract from the fruit of Ocotea heterochroma Mez & Sodiro ex Mez as well as the known compounds β-friedelanol (2), meso-dehydroguaiaretic acid (3), and yangambin (4), whose structures were elucidated on the basis of their comprehensive spectroscopic analysis including 2D NMR data. Lethality
bioassay using brine shrimp (Artemia salina Leach) was evaluated with the ethanol extract from the Ocotea heterochroma’s fruit. The toxicity of this extract was greater than the toxicity of those fractions obtained in a first solvent partition
(benzene, ethyl acetate, and butanol subfractions) and that of a mixture of acetylated 2′-epimers from the new neolignan 1.
Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 158–160, March–April, 2009. 相似文献
11.
The enzymatic synthesis of three isotopomers of l-DOPA labeled with deuterium and tritium at α carbon atom was elaborated. These compounds were converted into [(1S)-2H]–, [(1S)-
3H]–, and doubly labeled [(1S)-2H/3H]-dopamines using enzyme tyrosine decarboxylase. Doubly labeled (1R) isotopologue, i.e., [(1R)-2H/3H]-dopamine, was afforded by enzymatic decarboxylation of authentic l-DOPA carried out in deuteriated and tritiated incubation medium. 相似文献
12.
A. A. Kicha A. I. Kalinovskii N. V. Ivanchina V. A. Stonik 《Russian Chemical Bulletin》1998,47(10):2032-2033
A new polyhydroxysteroid was isolated from the starfishLuidiaster dawsoni; the structure of the product was established as (24S,25R)-24-methylcholestane-3β, 5α, 6β, 15α, 16β, 26-hexaol. A mixture of methyl-α- and β-d-glucopyranosides was also isolated from the extract of this starfish.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2088–2090, October, 1998. 相似文献
13.
Ya. A. Gur’eva O. A. Zalevskaya L. L. Frolova I. N. Alekseev A. V. Kuchin 《Chemistry of Natural Compounds》2011,46(6):920-923
The new chiral derivatives of benzylamine and 2α-hydroxypinan-3-one (1R,2R,5R)-3-[(1S)-α-methylbenzylamino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (2), (1S,2S,3S,5S)-3-(benzylamino)-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (3), and (1R,2R,3R,5R)-3-[(1S)-α-methylbenzylamino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (4) were synthesized and characterized. It was shown that reduction
of the benzylimines by sodium triacetoxyborohydride formed stereoselectively 3β-substituted pinanamines. 相似文献
14.
Zhiping Wu Yu Chen Xu Feng Bing Xia Ming Wang Yunfa Dong 《Chemistry of Natural Compounds》2009,45(6):829-833
Two new ceramides were isolated from the bulbs of Zephyranthes candida. Their structures were established as (2S,3S,4R,13E)-1,3,4-trihydroxy-2-[(2′R)-2′-hydroxytetracosanoylamino]-13-octadecene, named zephyranamide A (1) and (2S,3S,4R)-1,3,4-trihydroxy-2-octacosanoylaminohexadecene, named zephyranamide B (2). The structures of the new compounds were elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, DEPT, and COSY. 相似文献
15.
I. V. Borisova N. N. Zemlyanskii A. K. Shestakova Yu. A. Ustynyuk E. A. Chernyshev 《Russian Chemical Bulletin》2000,49(5):920-928
A method for the synthesis of a new class of betaines,viz., R3
1P+CR2R3SiR4R5S−, was developed. The experimental evidence for the intermediate formation of betaines R3
1P+−CR2R3−CR4R5−S− in the Wittig reaction for a series of thiocarbonyl compounds was obtained. A comparative analysis of the NMR spectra of
betaines containing the+P−C−Si−S− and+P−C−C−S− fragments was performed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 922–930, May, 2000. 相似文献
16.
V. V. Dotsenko S. G. Krivokolysko A. N. Chernega V. P. Litvinov 《Russian Chemical Bulletin》2007,56(7):1431-1436
A new stereoselective method for the synthesis of trans-isomers of 2-amino-4-aryl-5-benzoyl-4,5-dihydrothiophene-3-carbonitriles was proposed. The method involves base-catalyzed
reactions of phenacyl thiocyanate with 3-(het)aryl-2-cyanoprop-2-enethioamides. (4R,5S/4S,5R)-2-Amino-5-benzoyl-4-(2-chlorophenyl)-4,5-ihydrothiophene-3-carbonitrile was structurally characterized by X-ray diffraction
analysis.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1379–1383, July, 2007. 相似文献
17.
S. M. Adekenov A. T. Kulyjasov V. A. Raldugin I. Yu. Bagryanskaya Yu. V. Gatilov M. M. Shakirov 《Russian Chemical Bulletin》1998,47(1):169-172
A new germacranolide, ajanolide A, was isolated from aerial parts ofAjania fruticulosa by means of extraction with CHCl3 and adsorption chromatography. This compound was identified as (1(10)E,3S,4Z,6R,7S,11R)-3-acetoxygermacra-1(10),4-dien-12,6-olide ((1S,7S,10R,13R)-7-acetoxy-4,8,13-trimethyl-11-oxabicyclo[8.3.0]trideca-4(E),8(Z)-dien-12-one) by X-ray diffraction analysis. 2D1H−1H (COSY) and13C−1H (COSY) NMR spectroscopy was used for assigning the1H and13C NMR signals in the spectra of ajanolide A.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 167–170, January, 1998. 相似文献
18.
I. M. Gella N. S. Pivnenko L. A. Kutulya T. G. Drushlyak A. Yu. Kulikov N. B. Novikova 《Russian Chemical Bulletin》2005,54(10):2406-2416
Methylenation of (3R,6R)-2-(4-X-benzylidene)-6-isopropyl-3-methylcyclohexanones (X = F, Cl, Ph) with dimethylsulfoxonium methylide occurs stereoselectively
to give 1(S)-(4-X-phenyl)-5(R)-isopropyl-8(R)-methyl-3(R)-spiro[2.5]octanones, whose stereochemistry was established by 1H NMR spectroscopy. The configuration of the chiral centers in the cyclohexanone fragment and its preferred conformation (methyl
is axial and isopropyl is equatorial) in the products do not change with respect to the starting enones. The mutual trans-arrangement of the carbonyl and aryl groups at the newly formed three-membered ring was established; the aryl group also
occupies the trans-position with respect to the axial methyl group of the cyclohexanone fragment. Using methylenation of the compound with X
= Ph as an example, a mixture of by-products resulting from oxidative hydroxylation at the α-position relative to the carbonyl
group was isolated. The resulting chiral spiro[2.5]octanones induce a helical supramolecular ordering in the nematic mesophase
of 4-pentyl-4′-cyanobiphenyl and exhibit a twisting power only somewhat (by 20–30%) lower than the starting enones.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2331–2341, October, 2005. 相似文献
19.
Two dimeric proanthocyanidines identified as 2R,3R,4R-(-)-epigallocatechin-(4β→ 8)-2R,3R-(-)-epigallocatechin-3-O-gallate and 2R,3R,4R-(-)-epigallocatechin-(4β→8)-(-)-2R,3R,3,5,7,3′,4′,6′-hexahydroxyflavan were isolated by adsorption chromatography over polyamide of the ethylacetate fraction of
the aqueous alcohol extract of Limonium gmelinii roots. The former proanthocyanidine was isolated for the first time from sea lavender whereas the latter is new.
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Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 134–138, March–April, 2006. 相似文献
20.
Cycloadsurgenin, 20R,24 S-epoxycycloartan-6α,25-diol-3,16-dione, was partially synthesized in four steps from cyclosieversigenin. Side products with the structures 17E,24S-cycloart-17-en-6α,24,25-triol-3,16-dione and 17Z,24 S-cycloart-17-en-6α,24,25-triol-3,16-dione were obtained in addition to the desired product.
Presented at the 1st International Symposim on Edible Plant Resources and the Bioactive Ingredients, Xinjiang, China, July
25–27, 2008.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 591–595, November–December, 2008. 相似文献