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1.
Zhiping Wu Yu Chen Xu Feng Bing Xia Ming Wang Yunfa Dong 《Chemistry of Natural Compounds》2010,46(2):187-191
From the the bulbs of Zephyranthes candida (Amaryllidaceae), another two novel ceramides have been isolated and identified. The structures of the two novel compounds
were established as (2S,3S,4R,21E,2′R)2-[N-(2′-hydroxynonadecanoyl)-N-(1′′,2′′-dihydroxyethyl)amino]-21-hexacosene-1,3,4-triol, named zephyranamide C (1), and 1,3,4,5,6-pentahydroxy-2-(2′-hydroxyhexacosanoyl-amino)-18-(E)-tetracosene, named zephyranamide D (2). Their structures and stereochemistries were elucidated by spectral techniques including 1H NMR, 13C NMR, as well as HSQC, HMBC, DEPT, and COSY. 相似文献
2.
Lutz Preu Wolfgang Kliegel Steven J. Rettig James Trotter 《Monatshefte für Chemie / Chemical Monthly》2001,132(10):1213-1224
Summary. The structure of the dehydrogenation product 1′,3a′-dihydro-3′-((1,3-dioxoindan-2-ylidene)-phenyl-methyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′-(5′H, 6a′H)-tetrone derived from the cycloadducts (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((R)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone and/or (±)-(3a′S,6a′R)-1′,3a′-dihydro-3′-((S)-α-(1,3-dioxoindanyl)-benzyl)-5′-phenyl-spiro-(indan-2,1′-pyrrolo[3,4-c]pyrrole)-1,3,4′,6′(5H,6a′H)-tetrone, which were synthesized by 1,3-dipolar cycloaddition of N-phenylmaleimide to 2-((2-(1,3-dioxoindan-2-yl)-2-phenyl-ethenyl)-imino)-indan-1,3-dione,
was determined by X-ray analysis. Crystal data (CCD, 180 K): rhombohedral, R&3macr;;, a = 34.0871(7), c = 13.9358(5) ?, Z = 18; the structure was solved by direct methods and refined by full-matrix least-squares procedures to R(F, I ≥ 3σ(I)) = 0.053. The molecule contains a central folded ring system of two cis-fused 5-membered heterocyclic rings; each ring is nearly planar, and the angle between the rings amounts to 59.0°. Dynamic
1H NMR spectroscopy of the product revealed an exchange process caused by restricted rotation of the double bonded 1,3-indandione
moiety and the phenyl group about the Csp2-Csp2 single-bonds. Molecular modeling and complete lineshape analysis indicated a four site exchange process for which free energies
of activation and free energies could be established. ΔG
‡ values for the barriers of rotation are in the range of 57–59 kJ · mol − 1 at 273 K, which is unusually high for an unsubstituted phenyl group.
Received May 3, 2001. Accepted (revised) June 8, 2001 相似文献
3.
Preparative synthesis of the Corey chiral controller for enantioselective dihydroxylation of olefins
A five-step synthesis of both enantiomers of 1,2-di(2,4,6-trimethylbenzylamino)-1,2-diphenylethane,i.e., Corey (R,R)- and (S,S)-controllers for enantioselective dihydroxylation of olefins by osmium tetroxide, starting from α,α′-diphenylglyoxime, has
been developed. The key operations in the synthesis are the optical resolution of intermediaterac-1,2-diamino-1,2-diphenylethane into two enantiomers using only (R,R)-tartaric acid and the subsequent enhancement of the enantiomeric purity to >98% by crystallizations of the corresponding
Schiff's bis-bases. Analysis of the enantiomeric purity of the controllers can be easily performed using1H NMR spectra of their salts with (R)-α-methoxy-α-(trifluoromethyl)phenylacetic acid (MosherR-acid).
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 101–105, January, 1997. 相似文献
4.
Yakup Baran Ismet Kaya Murat Turkyılmaz 《Journal of Thermal Analysis and Calorimetry》2012,107(3):869-875
The new tetradentate symmetrical (2R,2′S)-1,1′-piperazine-1,4-diyldipropane-2-thiol) (L1), (2S)-1-[bis(2-aminoethyl)amino]propan-2-ol) (L2), and 2-{(E)-[((1R,2S)-2-{[(1Z)-(2-hydroxy phenyl)methylene]amino}cyclohexyl)imino]methyl}phenol (L3) ligands were synthesized and characterized on the basis of FT-IR, 1H, 13C NMR, EI mass, and elemental analysis. Three commercially available ligands, (2,2′-[ethane-1,2-diylbis(thio)]diethanol (L4), 2,2′-dithiodiethanenamine (L5), and (2,2′-[ethane-1,2-diyldi(imino)] diethanol (L6), were also studied. Pt(II) complexes were characterized by FTIR, elemental analysis and thermal methods. Thermal behaviors
of these complexes were investigated in the range 10–1000 °C. Magnetic properties were also studied, and the all complexes
were found to be diamagnetic. The structures consist of the monomeric units in which the Pt(II) atoms exhibit square planar
geometry. N,N′-bis(salicylidene)-1,2-cyclohexane has been synthesized and characterized by X-ray single crystal diffraction measurement.
The ligand crystallizes in monoclinic crystal system and space group, Cc. 相似文献
5.
Dong-yan Liu Xiao-feng Shi Dong-dong Wang Fu-jiang He Qu-huan Ma Bin Fan 《Chemistry of Natural Compounds》2011,47(5):704-707
Two new myricetin glycosides, myricetin-3-O-(6″-O-E-p-coumaroyl)-α-D-glucocopyranoside (1) and 3′,5′-di-O-methylmyricetin-3-O-(6″-O-acetyl)-α-D-glucopyranoside (2), and three known flavonoids, myricetin (3), cedrin (4), and 2R,3R-dihydromyricetin (5), were isolated from the pine needles of Cedrus deodara. Their structures were elucidated on the basis of extensive spectroscopic
analysis and chemical evidence. 相似文献
6.
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
7.
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
8.
L. T. Eremenko L. B. Romanova M. E. Ivanova D. A. Nesterenko V. S. Malygina A. B. Ermeev G. V. Lagodzinskaya V. P. Lodygina 《Russian Chemical Bulletin》1998,47(6):1137-1140
NewN,N′-bis- andN,N,N′, N′-tetrakis-hydroxyalkyl-substituted 1,4-cubanedicarboxamides were synthesized. Nitration of these compounds yielded the corresponding
nitrates. The reaction of 1,4-cubanedicarboxylic acid dichloride with ethylene glycol mononitrate and glycerol dinitrate gave
ester 1,4-[R1R2CHOC(O)]2C8H6, where R1=H and R2=CH2ONO2; and R1=R2=CH2ONO2, respectively. The cardiopharmacological activity of some of the synthesized compounds was determined. This allowed us to
find for the first time cubane derivatives that exhibit this kind of biological activity. The antiischemic activity of one
of these compounds,N,N′-bis(2-nitroxythyl)-1,4-cubanedicarboxdiamide, is higher than that of the well-known Nicorandil.
For Part 2, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1169–1172, June, 1998. 相似文献
9.
Solution equilibrium studies on Cu2+–L1–L2 ternary systems have been performed by pH-potentiometry, UV–Vis spectrophotometry and EPR methods (L1 corresponds to polyamines such as ethylenediamine (en), diethylenetriamine (dien), or N,N,N′,N′,N″-pentamethyldiethylenetriamine (Me5dien) and L2 represents 1-aminoethylphosphonic acid (α-alaninephosphonic acid)). The obtained results suggest the formation of heteroligand complexes with [Cu(L1)(α-Ala(P))] stoichiometry in all studied systems. Additionally, in the system with en the [Cu(en)(α-Ala(P))H−1]− species is formed in basic solution. Our spectroscopic results indicate tetragonal geometry for the [Cu(en)(α-Ala(P))] species, geometry slightly deviated from square pyramidal for the [Cu(dien)(α-Ala(P))] complex and strongly deviated from square pyramidal towards trigonal bipyramidal for the [Cu(Me5dien)(α-Ala(P))] species. The coordination modes in these heteroligand complexes are discussed. 相似文献
10.
Ding-Wa Zhang Zheng-Yin Yang Shi-Ping Zhang Ru-Dong Yang 《Transition Metal Chemistry》2006,31(3):333-336
A novel ligand (H2L), diethylenetriamine-N,N′,N′′-triacetylisoniazide N,N′′-bisacetic acid, and its four non-ion transition metal complexes,
ML · nH2O (M = Mn, n = 4; M = Co, Ni, n = 2; M = Cu, n = 1), have been synthesized and characterized on the basis of elemental analysis, molar conductivity, 1H-NMR, FAB-MS, TG-DTA analysis and IR spectrum. In addition, relaxivity (R1) of the complexes was determined, the relaxivity of MnL, CoL, NiL, CuL as well as Gd(DTPA)2− used as a control are 6.94, 2.79, 2.52, 1.59 and 4.34 l mmol−1 s−1, respectively. The relaxivity of MnL is larger than that of Gd(DTPA)2−. The results show that the complex of MnL may be a potential MRI contrast agent. 相似文献
11.
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
12.
A. V. Timshina S. A. Rubtsova I. N. Alekseev P. A. Slepukhin A. V. Kuchin 《Russian Journal of Organic Chemistry》2010,46(3):363-367
(1R,1′R,2S,4R)-1,7,7-Trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′-oxide, (1R,2S,3′R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′-trioxide, and (1R,4R)-1,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2′-[1,3]dithiolane] 1′,1′,3′,3′-tetraoxide were synthesized by oxidation of
camphor ethylene dithioacetal with m-chloroperoxybenzoic acid at different substrate-tooxidant ratios. The structure of the products was proved by IR and NMR
spectroscopy and X-ray analysis. 相似文献
13.
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
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.
X. F. Wang J. Gao J. Wang Zh. H. Zhang Y. F. Wang L. J. Chen W. Sun X. D. Zhang 《Journal of Structural Chemistry》2008,49(4):724-731
The title compounds, (NH4)2[MnII(edta)(H2O)]·3H2O (H4edta = ethylenediamine-N,N,N′,N′-tetraacetic acid), (NH4)2[MnII(cydta)(H2O)]·4H2O (H4cydta = trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid) and K2[MnII(Hdtpa)]·3.5H2O (H5dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), were prepared; their compositions and structures were determined
by elemental analysis and single-crystal X-ray diffraction technique. In these three complexes, the Mn2+ ions are all seven-coordinated and have a pseudomonocapped trigonal prismatic configuration. All the three complexes crystallize
in triclinic system in P-1 space group. Crystal data: (NH4)2[MnII(edta)(H2O)]·3H2O complex, a = 8.774(3) ?, b = 9.007(3) ?, c = 13.483(4) ?, α = 80.095(4)°, β = 80.708(4)°, γ = 68.770(4)°, V = 972.6(5) ?3, Z = 2, D
c = 1.541 g/cm3, μ = 0.745 mm−1, R = 0.033 and wR = 0.099 for 3406 observed reflections with I ≥ 2σ(I); (NH4)2[MnII(cydta)(H2O)]·4H2O complex, a = 8.9720(18) ?, b = 9.4380(19) ?, c = 14.931(3) ?, α = 76.99(3)°, β = 83.27(3)°, γ = 75.62(3)°, V = 1190.8(4)?3, Z = 2, D
c = 1.426 g/cm3, μ = 0.625 mm−1, R = 0.061 and wR = 0.197 for 3240 observed reflections with I ≥ 2σ(I); K2[MnII(Hdtpa)]·3.5H2O complex, a = 8.672(3) ?, b = 9.059(3) ?, c = 15.074(6) ?, α = 95.813(6)°, β = 96.665(6)°, γ = 99.212(6)°, V = 1152.4(7) ?3, Z = 2, D
c = 1.687 g/cm3, μ = 1.006 mm−1, R = 0.037 and wR = 0.090 for 4654 observed reflections with I ≥ 2σ(I).
Original Russian Text Copyright ? 2008 by X. F. Wang, J. Gao, J. Wang, Zh. H. Zhang, Y. F. Wang, L. J. Chen, W. Sun, and X.
D. Zhang
The text was submitted by the authors in English. Zhurnal Strukturnoi Khimii, Vol. 49, No. 4, pp. 753–759, July–August, 2008. 相似文献
16.
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
17.
Summary. Rh(III) polypyridine complexes ([Cp
*Rh(ppy)(H2O)]2+; ppy = 2,2′-bipyridine, 2,2′-bipyridine-4,4′-dicarboxylate, o-phenanthroline, tetrahydro-4,4′-dialkyl-bis-oxazole) oxidize in organic or aqueous alkaline solution primary and secondary alcohols to aldehydes or ketones and are thereby
reduced to the Rh(I) complexes Cp
*Rh(ppy). The Rh(III) form can be regenerated byoxidants like pyruvate or oxygen, making the reaction quasi-catalytic. The reaction follows anautocatalytic pathway; hydrogen transfer from the α-CH2 group of an alcoholate complex [Cp
*Rh(ppy)(OR)]+ to Cp
*Rh(I)(ppy) is suggested to yield the Rh(II) intermediate Cp
*Rh(ppy)H as the key and rate determining step. The knowledge of Rh(III)/Rh(I) redox potentials allows to estimate the thermodynamic
driving force of the reaction which is not more than about 300 mV. 相似文献
18.
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
19.
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
20.
E. V. Levina A. I. Kalinovskii P. V. Andriyashchenko P. S. Dmitrenok 《Russian Chemical Bulletin》2008,57(11):2431-2436
Two new polar steroidal glycosides identified as sodium (20R,22E,24R,25S)-3-O-(β-d-xylopyranosyl)-24-methyl-5α-cholest-22-ene-3β,6β,8,15α,26-pentol 26-sulfate (evasterioside A) and sodium (20R,22E)-24-O-(β-d-xylopyranosyl)-5α-cholest-22-ene-3β,6β,8,15α,24-pentol 3-sulfate (evasterioside B) were isolated from the Pacific starfish
Evasterias retifera collected in the Sea of Japan. Five known compounds, viz., coscinasterioside B, aphelasterioside A, marthasterone 3-sulfate and (20R)-cholest-7-en-3β-ol and cholesterol sulfates, were identified. The structures of the new natural compounds were established
using their 2D NMR and mass spectra and some chemical transformations. 相似文献