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1.
Richard C. Cambie Clifton E. F. Rickard P. Stewart Rutledge Keri D. Wellington 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):958-960
The sponge Hamigera tarangaensis has yielded eight new compounds and we report here the structure of one of these compounds, hamigeran A, C20H25BrO5, or methyl 7‐bromo‐4β,6‐dihydroxy‐1β‐isopropyl‐3aα,8‐dimethyl‐5‐oxo‐1a,3a,4,5‐tetrahydrocyclopenta[a]naphthalene‐4‐carboxylate, and the decomposition product of hamigeran D, C21H28BrNO4, namely 2‐(8‐bromo‐2β,7‐dimethyl‐4‐oxo‐1,3α‐benzoxazan‐5‐yl)‐3‐isopropylcyclopentylacetic acid. 相似文献
2.
Hugh W. Thompson Andrew P. J. Brunskill Roger A. Lalancette 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1507-1509
In the monohydrate of the title compound, (+)‐2β,4aα‐dihydroxy‐1,7‐dimethyl‐8‐oxo‐4bβ,7α‐gibbane‐1α,10β‐dicarboxylic acid‐1,4a‐lactone, C19H24O6·H2O, intermolecular hydrogen bonding progresses helically along b from carboxyl to ketone [O?O = 2.694 (5) Å]. The carboxyl and lactone carbonyl groups in translationally related molecules within a helix both accept hydrogen bonds from the same water of hydration. The oxygen of this water in turn accepts a hydrogen bond from the hydroxyl group of a third screw‐related molecule in an adjacent counterdirectionally oriented helix, yielding a complex three‐dimensional hydrogen‐bonding array. Intermolecular O?H—C close contacts were found to the carboxyl and lactone carbonyls, the hydroxyl, and the water. 相似文献
3.
Arindam Mukherjee Robert W. Gable Colette Boskovic 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):m71-m73
The molecule of the title compound, tetra‐μ2‐acetato‐diaquadi‐μ2‐chloro‐tetrachlorotetrakis[μ4‐3‐hydroxy‐2,2‐bis(oxidomethyl)propanolato]tetramethanoldi‐μ3‐methanolato‐di‐μ5‐oxo‐octamanganese(II)tetramanganese(III), [Mn4IIIMn8II(CH3O)2(C2H3O2)4(C5H9O4)4Cl6O2(CH4O)4(H2O)2], displays a centre of symmetry. The structure of the {Mn4IIIMn8IIO18Cl2}10− core is composed of three layers and features two oxo ligands binding in a rare μ5‐mode. 相似文献
4.
Anthony Linden Ihsan alis Markus Neuburger Otto Sticher 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):616-618
The title compound, [2aS‐(2aα,4aα,5α,7bα)]‐5‐(β‐d ‐glucopyranosyloxy)‐2a,4a,5,7b‐tetrahydro‐1‐oxo‐1H‐2,6‐dioxacyclopent[cd]inden‐4‐ylmethyl acetate monohydrate, C18H22O11·H2O, was extracted from the Turkish plant Putoria calabrica (L. fil.) DC. The three fused rings have envelope or distorted envelope conformations and form a bowl in which ring strain causes distortion of some bond angles and significant pyramidalization of two of the Csp2 atoms. The ring junction H atoms are all cis to one another and the glycosidic linkage is in the β axial position. The structure incorporates two symmetry‐independent water molecules, each of which is located on a twofold axis. Intermolecular hydrogen bonds involving all the hydroxy groups and water molecules link the molecules into a complex three‐dimensional framework. 相似文献
5.
Claude Didierjean Julien Marin Emmanuel Wenger Jean‐Paul Briand Andr Aubry Gilles Guichard 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):o200-o203
X‐ray studies reveal that tert‐butyl (6S)‐6‐isobutyl‐2,4‐dioxopiperidine‐1‐carboxylate occurs in the 4‐enol form, viz. tert‐butyl (6S)‐4‐hydroxy‐6‐isobutyl‐2‐oxo‐1,2,5,6‐tetrahydropyridine‐1‐carboxylate, C14H23NO4, when crystals are grown from a mixture of dichloromethane and pentane, and has an axial orientation of the isobutyl side chain at the 6‐position of the piperidine ring. Reduction of the keto functionality leads predominantly to the corresponding β‐hydroxylated δ‐lactam, tert‐butyl (4R,6S)‐4‐hydroxy‐6‐isobutyl‐2‐oxopiperidine‐1‐carboxylate, C14H25NO4, with a cis configuration of the 4‐hydroxy and 6‐isobutyl groups. The two compounds show similar molecular packing driven by strong O—H⋯O=C hydrogen bonds, leading to infinite chains in the crystal structure. 相似文献
6.
Carlo Andrea Mattia Alessandra Braca Nunziatina De Tommasi Raffaella Puliti 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):o644-o646
The title tetracyclic diterpenoid, 10,13,16,17‐tetrahydroxy‐9‐methyl‐15‐oxo‐20‐norkaurane‐18,10‐carbolactone hemihydrate, C20H28O6·0.5H2O, is a plant metabolite from Parinari sprucei, part of the Venezuelan Amazon flora. The asymmetric unit consists of two nearly identical molecules of the diterpenoid and one molecule of water. Some of the geometric parameters reflect steric strain in the molecule. The extended structure is characterized by hydrogen bonds and weaker hydrogen‐mediated interactions, which involve all of the hydroxy groups and propagate in sheets that coincide with the (002) family of planes. The water molecule acts as a double hydrogen‐bond donor and single acceptor and thus plays a critical role in the pattern of intermolecular interactions. 相似文献
7.
Paul G. Jene Christopher G. Pernin James A. Ibers 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(6):730-734
The X‐ray structure of 1,2,4,5‐tetrahydroxybenzene (benzene‐1,2,4,5‐tetrol) monohydrate, C6H6O4·H2O, (I), reveals columns of 1,2,4,5‐tetrahydroxybenzene parallel to the b axis that are separated by 3.364 (12) and 3.453 (11) Å. Molecules in adjacent columns are tilted relative to each other by 27.78 (8)°. Water molecules fill the channels between the columns and are involved in hydrogen‐bonding interactions with the 1,2,4,5‐tetrahydroxybenzene molecules. The crystal structure of the adduct 1,2,4,5‐tetrahydroxybenzene–2,5‐dihydroxy‐1,4‐benzoquinone (1/1), C6H6O4·C6H4O4, (II), reveals alternating molecules of 1,2,4,5‐tetrahydroxybenzene and 2,5‐dihydroxy‐1,4‐benzoquinone (both lying on inversion centers), and a zigzag hydrogen‐bonded network connecting molecules in three dimensions. For compound (II), the conventional X‐ray determination, (IIa), is in very good agreement with the synchrotron X‐ray determination, (IIb). When differences in data collection temperatures are taken into account, even the displacement parameters are in very good agreement. 相似文献
8.
Yan‐Ping Li Pin Yang Zi‐Xiang Huang Fu‐Xin Xie 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):m122-m124
The cyano‐bridged heteronuclear coordination polymer poly[tris[(5,12‐dimethyl‐7,14‐diphenyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene)copper(II)]‐hexa‐μ‐cyano‐bis[tricyanocobalt(III)] dimethylformamide solvate trihydrate], {[Cu3Co2(CN)12(C24H32N4)3]·C3H7NO·3H2O}n, was synthesized by the assembly reaction of [CuL]2+ (L is 5,12‐dimethyl‐7,14‐diphenyl‐1,4,8,11‐tetraazacyclotetradeca‐4,11‐diene) and [Co(CN)6]3− in a dimethylformamide–water solution. The structure consists of neutral cyano‐bridged Cu3Co2 units with the unique Co atom in a general position and all three Cu atoms on independent inversion centres. Each [Co(CN)6]3− ion connects three CuII ions via three cyano groups to form a novel cyano‐bridged two‐dimensional stair‐shaped‐layer structure. The water and dimethylformamide molecules are situated in the inter‐fragment spaces. 相似文献
9.
Ana María Atria Ricardo Baggio María Teresa Garland Piedad Corts 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m311-m314
The three title compounds, namely 4‐phenyl‐1H‐imidazolium hexa‐μ2‐chloro‐chloro‐μ4‐oxo‐tris(4‐phenyl‐1H‐imidazole‐κN1)tetracopper(II) monohydrate, (C9H9N2)[Cu4Cl7O(C9H8N2)3]·H2O, hexa‐μ2‐chloro‐μ4‐oxo‐tetrakis(pyridine N‐oxide‐κO)tetracopper(II), [Cu4Cl6O(C5H5NO)4], and hexa‐μ2‐chloro‐tetrakis(2‐methyl‐1H‐imidazole‐κN1)‐μ4‐oxo‐tetracopper(II) methanol trisolvate, [Cu4Cl6O(C4H6N2)4]·3CH4O, exhibit the same Cu4OCl6 framework, where the O atom at the centre of an almost regular tetrahedron bridges four copper cations at the corners. This group is in turn surrounded by a Cl6 octahedron, leading to a rather globular species. This special arrangement of the CuII cations results in a diversity of magnetic behaviours. 相似文献
10.
HongPing He JianXin Zhang YueMao Shen YiNeng He ChangXiang Chen XiaoJiang Hao 《Helvetica chimica acta》2002,85(2):671-677
Five new tetranortriterpenoids, (11β)‐21,23‐dihydro‐11,21‐dihydroxy‐23‐oxoobacunone (=21,23‐dihydro‐21‐hydroxy‐23‐oxozapoterin; 2 ), (11β)‐21,23‐dihydro‐11,23‐dihydroxy‐21‐oxoobacunone (=21,23‐dihydro‐23‐hydroxy‐21‐oxozapoterin; 3 ), (1α,11β)‐1,2,21,23‐tetrahydro‐1,11,23‐trihydroxy‐21‐oxoobacunone (=21,23‐dihydro‐23‐hydroxy‐21‐oxoclausenarin; 4 ), (1α,11β)‐23‐ethoxy‐1,2,21,23‐tetrahydro‐1,11‐dihydroxy‐21‐oxoobacunone (=23‐ethoxy‐21,23‐dihydro‐21‐oxoclausenarin; 5 ); (11β)‐1,2,21,23‐tetrahydro‐11,23‐dihydroxy‐21‐oxoobacunoic acid; 6 ), were isolated from the aerial part of Clausena excavata Burm. f. (Rutaceae). All compounds possessed 3,4‐seco skeletons. Their structures were established by spectroscopic studies. Tetranortriterpenoids with a 4‐hydroxybut‐2‐eno‐4‐lactone moiety are rarely found in the genus Clausena. 相似文献
11.
Jan ejka Bohumil Kratochvíl Ivana Císaov Alexandr Jegorov 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o428-o430
Simvastatin, or (1S,3R,7S,8S,8aR)‐8‐{2‐[(2R,4R)‐4‐hydroxy‐6‐oxo‐3,4,5,6‐tetrahydro‐2H‐pyran‐2‐yl]ethyl}‐3,7‐dimethyl‐1,2,3,7,8,8a‐hexahydronaphthalen‐1‐yl 2,2‐dimethylbutanoate, C25H38O5, is almost isostructural with lovastatin, and the general conformational features are closely related to those of other reported crystal structures of statins. The only hydrogen bond present facilitates the formation of infinite chains of molecules along the b axis. 相似文献
12.
Ying‐Hong Lu Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak Zhen Shen Jing‐Lin Zuo Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):911-913
The title dinuclear di‐μ‐oxo‐bis[(1,4,8,11‐tetraazacyclotetradecane‐κ4N)manganese(III,IV)] diperchlorate nitrate complex, [Mn2O2(C10H24N4)2](ClO4)2(NO3) or [(cyclam)MnO]2(ClO4)2(NO3), was self‐assembled by the reaction of Mn2+ with 1,4,8,11‐tetraazacyclotetradecane in aqueous media. The structure of this compound consists of a centrosymmetric binuclear [(cyclam)MnO]3+ unit, two perchlorate anions and one nitrate anion. While the low‐temperature electron paramagnetic resonance spectra show a typical 16‐line signal for a di‐μ‐oxo MnIII/MnIV dimer, the magnetic susceptibility studies also confirm a characteristic antiferromagnetic coupling between the electronic spins of the MnIV and MnIII ions. 相似文献
13.
Timothy J. Hubin Nathaniel W. Alcock Daryle H. Busch 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):37-39
The preparation and crystal structures of (4,11‐dibenzyl‐1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐κ4N)copper(I) hexa‐fluorophosphate, [Cu(C26H38N4)]PF6, and acetonitrile(4,11‐dibenzyl‐1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐κ4N)‐copper(II) bis(hexafluorophosphate), [Cu(C2H3N)(C26H38‐N4)](PF6)2, are described. The CuI ion is tetracoordinated in a very distorted tetrahedron, while the CuII analogue is pentacoordinated in a square pyramid. 相似文献
14.
Neven Strukan Marina Cindri Tanja Kajfe Boris Kamenar Gerald Giester 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e443-e444
The crystal and molecular structure of bis(tetramethylammonium) dichlorotetra‐μ2‐methoxo‐di‐μ2‐oxo‐octooxotetramolybdate(VI), (C4H12N)2[Mo4O10(OCH3)4Cl2], has been determined from X‐ray diffraction data. The crystallographically centrosymmetric anion is built up of four edge‐sharing octahedra, two MoO6 and two MoO5Cl. 相似文献
15.
Claude Villiers Pierre Thury Michel Ephritikhine 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m243-m245
In the title compound, (1,4,7,10,13,16‐hexaoxacyclooctadecane‐1κ6O)‐μ‐oxo‐1:2κ2O:O‐hexakis(tetrahydroborato)‐1κ3H;2κ2H;2κ2H;2κ3H;2κ3H;2κ3H‐diuranium(IV), [U2(BH4)6O(C12H24O6)], one of the U atoms (U1), located at the centre of the crown ether moiety, is bound to the six ether O atoms, and also to a tridentate tetrahydroborate group and a μ‐oxo atom in axial positions. The other U atom (U2) is bound to the same oxo group and to five tetrahydroborate moieties, three of them tridentate and the other two bidentate. The two metal centres are bridged by the μ‐oxo atom in an asymmetric fashion, thus giving the species (18‐crown‐6)(κ3‐BH4)U=(μ‐O)—U(κ3‐BH4)3(κ2‐BH4)2, in which the U1=O and U2—O bond lengths to the μ‐O atom [1.979 (5) and 2.187 (5) Å, respectively] are indicative of the presence of positive and negative partial charges on U1 and U2, respectively. 相似文献
16.
(Borohydrido)(18‐crown‐6)potassium and (borohydrido)(dibenzo‐18‐crown‐6)(tetrahydrofuran)potassium
Claude Villiers Michel Ephritikhine Pierre Thury 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m275-m277
In the two compounds (borohydrido)(1,4,7,10,13,16‐hexaoxacyclooctadecane‐κ6O)potassium, [K(BH4)(C12H24O6)], (I), and (borohydrido)(1,4,7,10,13,16‐hexaoxa‐2,3:11,12‐dibenzocyclooctadeca‐2,11‐diene‐κ6O)(tetrahydrofuran)potassium, [K(BH4)(C4H8O)(C20H24O6)], (II), the K atom is bound to the six O atoms of the crown ether and to a tridentate borohydride group, with further coordination to a tetrahydrofuran molecule in (II). The alkali metal ion environment is thus distorted hexagonal–pyramidal in (I) and bipyramidal in (II). 相似文献
17.
Marco Crisma Fernando Formaggio Claudio Toniolo 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):695-696
Benzyl N‐[8‐(4,4‐dimethyl‐5‐oxo‐4,5‐dihydrooxazol‐2‐yl)‐2,5,5,8‐tetramethyl‐3,6‐dioxo‐4,7‐diazanon‐2‐yl]carbamate, C24H34N4O6, an oxazol‐5(4H)‐one from N‐α‐benzyloxycarbonyl‐(Aib)4‐OH (Aib = α‐aminoisobutyryl) represents the longest peptide oxazolone so far characterized by X‐ray diffraction. The overall geometry of the oxazolone ring compares well with literature data. The Aib(1) and Aib(2) residues are folded into a type III β‐bend, while the conformation adopted by Aib(3), preceding the oxazolone moiety, is semi‐extended. The disposition of the oxazolone ring relative to the preceding residue is stabilized by C—H?N and C—H?O intramolecular interactions. 相似文献
18.
Bernardo Masci Stefano Levi Mortera Pierre Thury 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(11):m482-m484
In the title compound, 4,7,13,16,21,24‐hexaoxa‐1,10‐diazoniabicyclo[8.8.8]hexacosane dioxo[7,13,21,27‐tetraphenyl‐3,17‐dioxapentacyclo[23.3.1.15,9.111,15.119,23]ditriaconta‐1(29),5,7,9(30),11(31),12,14,19(32),20,22,25,27‐dodecaene‐29,30,31,32‐tetraolato]uranium dimethyl sulfoxide trisolvate, (C18H38N2O6)[U(C54H40O6)O2]·3C2H6OS, the uranyl ion is bound to the four phenoxide groups of the deprotonated p‐phenyltetrahomodioxacalix[4]arene ligand in a cone conformation, resulting in a dianionic complex. The diprotonated [2.2.2]cryptand counter‐ion is located in the cavity defined by the eight aromatic rings of the homooxacalixarene, where it is held by cation–anion, cation–π and possibly C—H⋯π interactions. Dimerization in the packing leads to the formation of sandwich assemblages in which two diprotonated [2.2.2]cryptands are encompassed by two uranyl complexes. 相似文献
19.
Stefania Costa Pier Paolo Giovannini Giancarlo Fantin Alessandro Medici Paola Pedrini 《Helvetica chimica acta》2013,96(6):1062-1071
The biotransformations of hyodeoxycholic acid with various Rhodococcus spp. are reported. Some strains (i.e., Rhodococcus zopfii, Rhodococcus ruber, and Rhodococcus aetherivorans) are able to partially degrade the side chain at C(17) to afford 6α‐hydroxy‐3‐oxo‐23,24‐dinor‐5β‐cholan‐22‐oic acid ( 2 ; 23%) and 6α‐hydroxy‐3‐oxo‐23,24‐dinorchol‐1,4‐dien‐22‐oic acid ( 3 ; 23–30%), together with two new 9,10‐secosteroids 4 and 5 (10–45%), still bearing the partial side chain at C(17) and adopting an intramolecular hemiacetal form. In addition, the 9,10‐secosteroid 5 showed an unprecedented C(4)‐hydroxylation. The new secosteroids were fully characterized by MS, IR, NMR, and 2D‐NMR analyses. 相似文献
20.
Mohammed Bakir Petrea C. Facey Ishmael Hassan Willem H. Mulder Roy B. Porter 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(11):o798-o800
Mikanolide [systematic names: 1,10:2,3‐diepoxy‐6,8‐dihydroxy‐11‐vinylgermacr‐4‐ene 12,14‐di‐γ‐lactone and 7,10a‐dimethyl‐1a,1b,2a,6a,7,9a,10,10a‐octahydro‐4H‐6,3‐methenofuro[3,2‐c]bisoxireno[f,h]oxacycloundecin‐4,8(6H)‐dione], C15H14O6, derived from a variety of Mikania micrantha growing in Portland, Jamaica, contains a methylcyclodecane ring fused to an unsaturated planar α,γ‐lactone, an envelope‐type near‐planar vinyl‐β,γ‐lactone and two epoxide moieties. The crystal packing shows stacks of mikanolide molecules interlocked via a network of non‐classical C—H⋯O hydrogen bonds between the lactone units. 相似文献