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1.
Alan R. Kennedy Abedawn I. Khalaf Colin J. Suckling 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e265-e266
The title compound, C10H10O5, was found to exist as the endo–cis isomer with a pair of enantiomers in the asymmetric unit. The cyclohexene ring is folded about the methylene‐to‐CH(acetoxy) vector to give a boat conformation. 相似文献
2.
Angle Chiaroni Claude Riche Xavier Cachet Brigitte Deguin Michel Koch Franois Tillequin 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):358-359
The stereochemistry of the title compound, C20H28O8, a key step in the preparation of analogues of mannostatins, potent inhibitors of α‐mannosidase, has been established. The carboxylic acid group at C1 unexpectedly eclipses the C1—C2 bond. The cyclopropane ring makes a dihedral angle of 109.4 (2)° with the cyclopentene ring. 相似文献
3.
Florence Popowycz Sandrine Gerber‐Lemaire Eliazar Rodriguez‐García Catherine Schütz Pierre Vogel 《Helvetica chimica acta》2003,86(6):1914-1948
The synthesis of 46 derivatives of (2R,3R,4S)‐2‐(aminomethyl)pyrrolidine‐3,4‐diol is reported (Scheme 1 and Fig. 3), and their inhibitory activities toward α‐mannosidases from jack bean (B) and almonds (A) are evaluated (Table). The most‐potent inhibitors are (2R,3R,4S)‐2‐{[([1,1′‐biphenyl]‐4‐ylmethyl)amino]methyl}pyrrolidine‐3,4‐diol ( 3fs ; IC50(B)=5 μM , Ki=2.5 μM ) and (2R,3R,4S)‐2‐{[(1R)‐2,3‐dihydro‐1H‐inden‐1‐ylamino]methyl}pyrrolidine‐3,4‐diol ( 3fu ; IC50(B)=17 μM , Ki=2.3 μM ). (2S,3R,4S)‐2‐(Aminomethyl)pyrrolidine‐3,4‐diol ( 6 , R?H) and the three 2‐(N‐alkylamino)methyl derivatives 6fh, 6fs , and 6f are prepared (Scheme 2) and found to inhibit also α‐mannosidases from jack bean and almonds (Table). The best inhibitor of these series is (2S,3R,4S)‐2‐{[(2‐thienylmethyl)amino]methyl}pyrrolidine‐3,4‐diol ( 6o ; IC50(B)=105 μM , Ki=40 μM ). As expected (see Fig. 4), diamines 3 with the configuration of α‐D ‐mannosides are better inhibitors of α‐mannosidases than their stereoisomers 6 with the configuration of β‐D ‐mannosides. The results show that an aromatic ring (benzyl, [1,1′‐biphenyl]‐4‐yl, 2‐thienyl) is essential for good inhibitory activity. If the C‐chain that separates the aromatic system from the 2‐(aminomethyl) substituent is longer than a methano group, the inhibitory activity decreases significantly (see Fig. 7). This study shows also that α‐mannosidases from jack bean and from almonds do not recognize substrate mimics that are bulky around the O‐glycosidic bond of the corresponding α‐D ‐mannopyranosides. These observations should be very useful in the design of better α‐mannosidase inhibitors. 相似文献
4.
Yoshiyuki Kani Shigeru Ohba Seiji Amano Noriko Ogawa Masami Ohtsuka Noritaka Chida 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):e222-e222
The relative configuration was determined for the title compound, C26H34O6, which was prepared in a synthetic study on immunosuppressant FR65814. There is an intramolecular hydrogen bond between the hydroxy and epoxy groups. 相似文献
5.
Yoann Coquerel Aurlien Blanc Jean‐Pierre Deprs Andrew E. Greene Marie‐Thrse Averbuch‐Pouchot Christian Philouze Andr Durif 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1480-1481
The title compound, C12H10Cl4O2, has a pseudoasymmetric centre at the methyl‐substituted carbon and, in the solid state, a boat‐like conformation. 相似文献
6.
Ferdinand Krner Markus Schürmann Hans Preut Wolfgang Kreiser 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):76-77
Esterification of a single diastereomer of 2‐(4‐methylenecyclohex‐2‐enyl)propanol, (II), with (1R,4S)‐(+)‐camphanic acid [(1R,4S)‐4,7,7‐trimethyl‐3‐oxo‐2‐oxabicyclo[2.2.1]heptane‐1‐carboxylic acid] leads to the crystalline title compound, C20H28O4. The relative configuration of the camphanate was determined by X‐ray diffraction analysis. The outcome clarifies the relative and absolute stereochemistry of the naturally occurring bisabolane sesquiterpenes β‐turmerone and β‐sesquiphellandrene, since we have converted (II) into both natural products via a stereospecific route. 相似文献
7.
The First Synthesis of (4S,5R,6R)‐5,6‐Dihydroxy‐4‐(prop‐1‐en‐2‐yl)cyclohex‐1‐ene‐1‐carboxylic Acid 下载免费PDF全文
Oleg V. Ardashov Yuliya S. Demidova Dina V. Korchagina Konstantin P. Volcho Irina L. Simakova Nariman F. Salakhutdinov 《Helvetica chimica acta》2015,98(10):1442-1455
A putative acid metabolite of a novel highly effective antiparkinsonian agent, (4S,5R,6R)‐5,6‐dihydroxy‐4‐(prop‐1‐en‐2‐yl)cyclohex‐1‐ene‐1‐carboxylic acid ( 5 ), was synthesized for the first time. Several synthetic approaches based on different transformations of O‐bearing monoterpenoids of the pinane and p‐menthane series were developed and tested in the course of the study. Acid 5 was synthesized starting from a commercially available monoterpenoid, (?)‐verbenone, in a total yield of 4.4% over eight steps. 相似文献
8.
Haibing Zhou Yi Yuan Albert S. C. Chan Teng‐Kuei Yang Rugang Xie 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):e57-e57
The asymmetric unit of C20H19NO4 contains two molecules with slightly different conformations. In the crystal, the molecules are linked by O—H?O and N—H?O hydrogen bonds [O?O 2.764 (3) and 2.811 (3) Å; N?O 2.907 (3) and 2.968 (3) Å] to form a two‐dimensional network. 相似文献
9.
Gregory M. Sandala Dr. Borislav Kovačević Dr. Danijela Barić Dr. David M. Smith Dr. Leo Radom Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(19):4865-4873
Intriguing inactivation : Calculations suggest that the ability of relatively high‐energy radical intermediates to inactivate glycerol dehydratase (GDH) may reflect a general and hitherto unidentified inactivation mechanism in the reaction of coenzyme B12‐dependent enzymes and 3‐unsaturated 1,2‐diols (see scheme; AdoCbl: adenosylcobalamin or coenzyme B12).
10.
(−)‐ and (+)‐Conduramine B‐1 ((−)‐ and (+)‐ 5 , resp.) have been derived from (+)‐ and (−)‐7‐oxabicyclo[2.2.1]hept‐5‐en‐2‐one (‘naked sugars’ of the first generation). Although (−)‐ 5 imitates the structure of β‐glucosides, it does not inhibit β‐glucosidases but inhibits α‐mannosidases selectively. N‐Benzylation of (−)‐ 5 improves the potency of conduramine B‐1 as α‐mannosidase inhibitor and also generates compounds inhibiting β‐glucosidases. For instance, (−)‐N‐benzyl‐conduramine B‐1 ((−)‐ 19a ) is a competitive inhibitor of β‐glucosidase from almonds (IC50 = 32 μM , Ki = 10 μM ) and a weak inhibitor of α‐mannosidases from jack bean (IC50 = 171 μM ) and from almonds (IC50 = 225 μM ) whereas (−)‐N‐(4‐phenylbenzyl)conduramine B‐1 ((−)‐ 19g ) is a good inhibitor of α‐mannosidase from jack beans (IC50 = 29 μM , Ki = 4.8 μM ) and a weaker inhibitor of β‐glucosidase from almonds (IC50 = 32 μM , Ki = 7.8 μM ) (Table 1). 相似文献
11.
Ove Alexander Hgmoen strand Zeshan Iqbal Marcel Sandberg Eili T. Kase Carl Henrik Grbitz Pl Rongved 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(6):647-650
(2S,3S)‐2,6‐Dimethylheptane‐1,3‐diol, C9H20O2, (I), was synthesized from the ketone (R)‐4‐benzyl‐3‐[(2R,3S)‐3‐hydroxy‐2,6‐dimethylheptanoyl]‐1,3‐oxazolidin‐2‐one, C19H27NO4, (II), containing C atoms of known chirality. In both structures, strong hydrogen bonds between the hydroxy groups form tape motifs. The contribution from weaker C—H...O hydrogen bonds is much more evident in the structure of (II), which furthermore contains an example of a direct short Osp3...Csp2 contact that represents a usually unrecognized type of intermolecular interaction. 相似文献
12.
John Reglinski Michelle K. Taylor Alan R. Kennedy 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o169-o172
We have isolated and crystallographically characterized the three homologous compounds N,N′‐bis(2‐methoxybenzylidene)ethane‐1,2‐diamine (MeSalen), C18H20N2O2, N,N′‐bis(2‐methoxybenzylidene)propane‐1,3‐diamine (MeSalpr), C19H22N2O2, and N,N′‐bis(2‐methoxybenzylidene)butane‐1,4‐diamine (MeSalbu), C20H24N2O2. In contrast with MeSalpr, the molecules of MeSalen and MeSalbu, which have an even number of methylene units, have crystallographic symmetry. Comparing these methoxy‐substituted species with their hydroxy equivalents shows that the aryl rings rotate upon removal of the O—H⋯N hydrogen bonds. The packing of MeSalen and MeSalpr is controlled by C—H⋯π interactions, whereas that of MeSalbu has only van der Waals contacts. 相似文献
13.
Asymmetric synthesis of irnigaine was achieved starting from an enantiopure β-amino ester 5 using the condensation of amino al-cohol 2 with acetylacetone and the subsequent intramolecular cycllzation as the key steps. 相似文献
14.
A method is described for the qualitative and quantitative determination of configurational isomers of zeaxanthin (=3,3′ -dihydroxy-β, β -carotene) and lutein (=3,3′ -dihydroxy-α -cartotene). It is based on the reaction of these zeaxathin and lutein isomers with (S)-(+)-α-(1-naphthyl) ethyl isocyanate to afford diastereomeric dicarbamates, which are analyzed by HPLC. 相似文献
15.
The synthesis of sarcinaxanthin ((2R,6R,2′R,6′R)- 1 ), a symmetrical C50-carotenoid with two γ-end groups, isolated from Sarcina lutea and from Cellulomonas biazotea as major pigment, was based on the strategy C20 + C10 + C20 = C50 using camphoric acid as starting material for the C20-end group 3. The key step of the synthesis is a ring enlargement of the cyclopentane derivative 10 with 2,4,4,6-tetrabromocyclohexa-2,5-dien-1-one (TBCO) to give the cyclohexane derivative 11 (Scheme 1). The spectroscopic data of the synthetic compound are in full agreement with the data of the isolated product and give the final proof for the (2R,6R,2′R,6′R) chirality of natural sarcinaxanthin. 相似文献
16.
The changes of the specific rotation and sign of optically active BINOL have been studied in polar/non-polar solvents and at the different pH values of solvent.It is considered that these changes are determined by the equilibriurn studies between cisoid and transoid conformations of BINOL with the same configuration(R or S) which related to the change of the dihedral angle between two naphthalene ring planes of BINOL. 相似文献
17.
Pale yellow single crystals of [O=C(NPPh3)C(I)=C(NPPh3)‐C(NPPh3)2]+I‐·1.5 thf ( 1 ·1.5 thf) have been obtained by the reaction of INPPh3 with thallium in thf suspension. They are characterized by IR spectroscopy and by a crystal structure determination. 1 ·1.5 thf crystallizes in the monoclinic space group P21/n, Z = 4, lattice dimensions at ‐83?C: a = 1101.7(1), b = 3449.0(2), c = 2000.4(1) pm, β = 104.88(1)?, R1 = 0.0382. 1 can be understood as a cationic variation of (Z)‐2‐butenale in which all H atoms are substituted by triphenylphosphoraneimine residues and by a iodine atom, respectively. 相似文献
18.
Susanne Flock Clemens Bruhn Heinrich Fink Herbert Frauenrath 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):o101-o103
The title enantiomorphic compounds, C16H23NO4S, have been obtained in an enantiomerically pure form by crystallization from a diastereomeric mixture either of (2S,4S)‐ and (2R,4S)‐ or of (2R,4R)‐ and (2S,4R)‐2‐tert‐butyl‐4‐methyl‐3‐(4‐tolylsulfonyl)‐1,3‐oxazolidine‐4‐carbaldehyde. These mixtures were prepared by an aziridination rearrangement process starting with (S)‐ or (R)‐2‐tert‐butyl‐5‐methyl‐4H‐1,3‐dioxine. The crystal structures indicate an envelope conformation of the oxazolidine moiety for both compounds. 相似文献
19.
Huub Kooijman Anthony L. Spek Henk Kleijn Hendrik L. van Maanen Johann T. B. H. Jastrzebski Gerard van Koten 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):481-483
The configuration of the chiral ring atoms of the title compound, C26H26N2O, obtained in an enantioselective synthesis, has been established relative to the known R configuration of the α‐methylbenzyl moieties. The crystal packing involves a two‐dimensional network of C—H?π interactions between the aromatic rings. 相似文献
20.
The crystal and molecular structure of the complex containing cobalt-carbon and iron-sulfur cluster cores, (μ-p-CH3C6H4C2S) (μ-n-C3H7S)Fe2(CO)6Co2(CO)6, has been determined by X-ray diffraction method. The crystals are triclinic, space group P&1bar;, with a — 9.139(2), b=9.610(1), c-17.183(2) Å, α = 84.36(1), β-89.45(1), γ=88.15(1)°, V-1501.0 Å3; Z=2, Dc=1.74 g/cm3. R=0.072, Rw=0.081. The results of the structure determination show a cobalt-carbon cluster core formed through the reaction of (μ-p-CH3C6H4C2S)(μ-n-C3H7S)Fe2(CO)6 with Co2(CO)8. In the cobalt-carbon cluster core, the bond length of the original C≡C lengthened to 1.324 Å which is close to the typical value of carbon-carbon double bond. The groups connecting the carbons of the cluster core are in cis position and lie on the opposite side of cobalt atoms. In this complex, the conformation of —SC3H7 is e-type, while that of —SC2C6H4CH3 is a-type. 相似文献