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1.
K. Ravikumar B. Sridhar M. Mahesh V. V. Narayana Reddy 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o574-o576
The crystal structures of pyranoquinolines 9‐fluoro‐5‐phenyl‐3,4,4a,5,6,10b‐hexahydro‐2H‐pyrano[3,2‐c]quinoline, C18H18FNO, and 9‐methyl‐5‐phenyl‐3,4,4a,5,6,10b‐hexahydro‐2H‐pyrano[3,2‐c]quinoline, C19H21NO, are isomorphous. In both structures, the pyran ring is exo to the six‐membered N‐heterocyclic ring formed in the cycloaddition step. The torsion angles across the phenyl linkage for the two structures are −91.2 (1) and −88.3 (2)°. The striking feature in both crystal packings is that they do not contain the expected conventional hydrogen bonds, in spite of the presence of good hydrogen‐bonding functionalities. Possible C—H⋯π interactions are, however, observed. 相似文献
2.
K. Ravikumar M. Mahesh V. V. Narayana Reddy 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o887-o889
The structures of two diastereoisomers of 9‐chloro‐8‐fluoro‐4‐phenyl‐2,3,3a,4,5,9b‐hexahydrofuro[3,2‐c]quinoline, C17H15ClFNO, are very similar. The orientation of the furan ring, as a result of its fusion to the quinoline nucleus, constitutes the significant difference between the two structures. The dihedral angles between the furan and phenyl rings are 73.4 (1) and 63.8 (1)°. 相似文献
3.
Cline Besnard Christian Kloc Theo Siegrist Christer Svensson Krystian Pluta 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(6):o377-o379
The molecules of the title compound, C26H15N3S, have a pentacyclic ring system which is almost planar, with the central ring in a flattened boat conformation. The folding angle between the two quinoline rings is 6.75 (7)°. The 14‐phenyl substituent is in a quasi‐axial conformation, while the 14‐cyano substituent is in a quasi‐equatorial conformation with respect to the thiopyran ring. The S⋯C—Cphenyl and S⋯C—CCN angles are 116.8 (2) and 129.3 (2)°, respectively. The plane of the phenyl group is nearly coplanar with the plane bisecting the dihedral angle of the pentacyclic ring system. 相似文献
4.
Anthony Linden Miyase G. Gündüz Rahime imek Cihat afak 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o227-o230
A mixture of the RR/SS and RS/SR diastereoisomeric pairs of methyl 4‐(2,4‐dichlorophenyl)‐2,7‐dimethyl‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate, C19H19Cl2NO3, forms cocrystals in which there is one unique molecule in the asymmetric unit, but the molecule displays disorder in the region of the 7‐position of the quinoline ring system as a result of the random occurrence of the diastereoisomers at the same crystallographic site. A similar arrangement exists in the monohydrate cocrystals that form from a mixture of the RR/SS and RS/SR diastereoisomeric pairs of methyl 4‐(2,4‐dichlorophenyl)‐2‐methyl‐7‐phenyl‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxylate monohydrate, C24H21Cl2NO3·H2O. These compounds belong to a class of 1,4‐dihydropyridines whose members have calcium modulatory properties. The 1,4‐dihydropyridine rings have the usual shallow boat conformation. In each structure, the 2,4‐dichlorophenyl ring is oriented such that the 2‐chloro substituent is in a synperiplanar orientation with respect to the 1,4‐dihydropyridine ring plane. In each crystal structure, the molecules are linked into chains by N—H⋯O hydrogen‐bonding interactions. 相似文献
5.
Shiming Li Knut Lundquist Vratislav Langer 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(10):o625-o627
Compounds (2R*,3S*)‐1‐(3,4‐dimethoxyphenyl)‐3‐{3‐methoxy‐2‐[(2R*)‐tetrahydropyran‐2‐yloxy]phenyl}‐2,3‐epoxy‐1‐propanone, C23H26O7, (I), and trans‐1‐(3,4‐dimethoxyphenyl)‐3‐[3‐methoxy‐2‐(methoxymethoxy)phenyl]‐2,3‐epoxy‐1‐propanone, C20H22O7, (II), were obtained on epoxidation of chalcones. The stereochemistries of (I) and (II) were elucidated. In both compounds, the substituents on the oxirane ring are trans‐oriented. Compound (I) was obtained together with a diastereometric form that differs from (I) with respect to the configuration of the asymmetric C atom in the tetrahydropyran group. The geometries of the substituted oxirane rings of (I) and (II) are very similar. The hydrogen‐bonding patterns, mediated via weak C—H⋯O interactions, differ considerably. The crystal structures of (I) and (II) are compared with those of related chalcone epoxides. The conversion of (I) and (II) into lignin‐related phenylcoumarans is discussed. 相似文献
6.
Yavuz Kysal amil Ik Gülay ahin Erhan Palaska 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(9):o542-o544
The structures of N‐ethyl‐3‐(4‐fluorophenyl)‐5‐(4‐methoxyphenyl)‐2‐pyrazoline‐1‐thiocarboxamide, C19H20FN3OS, (I), and 3‐(4‐fluorophenyl)‐N‐methyl‐5‐(4‐methylphenyl)‐2‐pyrazoline‐1‐thiocarboxamide, C18H18FN3S, (II), have similar geometric parameters. The methoxy/methyl‐substituted phenyl groups are almost perpendicular to the pyrazoline (pyraz) ring [interplanar angles of 89.29 (8) and 80.39 (10)° for (I) and (II), respectively], which is coplanar with the fluorophenyl ring [interplanar angles of 5.72 (9) and 10.48 (10)°]. The pyrazoline ring approximates an envelope conformation in both structures, with the two‐coordinate N atom involved in an intramolecular N—H⋯Npyraz interaction. In (I), N—H⋯O and C—H⋯S intermolecular hydrogen bonds are the primary interactions, whereas in (II), there are no intermolecular hydrogen bonds. 相似文献
7.
A. Subbiah Pandi D. Velmurugan S. Shanmuga Sundara Raj Hoong‐Kun Fun P. R. Seshadri D. Thirumalai 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):821-824
10‐(4‐Fluorophenyl)‐3,3,6,6,9‐pentamethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C24H28FNO2, (I), crystallizes with two crystallographically independent molecules (which differ slightly in conformation), while 10‐(4‐fluorophenyl)‐9‐propyl‐3,3,6,6‐tetramethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C26H32FNO2, (II), crystallizes with one molecule per asymmetric unit. In both structures, the central ring in the acridine moiety is in a sofa conformation, while the outer rings adopt intermediate half‐chair/sofa conformations. The central pyridine ring is orthogonal to the substituted phenyl ring. In both structures, the packing of the crystal is stabilized by C—H?O intermolecular hydrogen bonds. 相似文献
8.
Peter G. Jones Ludger Ernst Ina Dix Lars Wittkowski 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):239-241
The [2.2]paracyclophane groups of the title compounds, chiral and meso‐bis(tricyclo[8.2.2.24,7]hexadeca‐4,6,10,12,13,15‐hexaen‐5‐yl)methane (the former as a racemate), C33H32, and meso‐bis(tricyclo[8.2.2.24,7]hexadeca‐4,6,10,12,13,15‐hexaen‐5‐yl) sulfide, C32H30S, show the characteristic structural features of the parent compound [2.2]paracyclophane and the related compound dimethylbis([2.2]paracyclophan‐4‐yl)silane, C34H36Si: the aromatic rings are puckered, resulting in a boat conformation. The planes of the four coplanar C atoms are slightly twisted with respect to each other. The Csp3—Csp3 bond lengths of the ethylene bridges are elongated by the electronic and steric effects of the skeleton. 相似文献
9.
Yoriko Sonoda Seiji Tsuzuki Nobuyuki Tamaoki Midori Goto 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):o196-o200
The crystal structures of the four E,Z,E isomers of 1‐(4‐alkoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, namely (E,Z,E)‐1‐(4‐methoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C19H17NO3, (E,Z,E)‐1‐(4‐ethoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C20H19NO3, (E,Z,E)‐1‐(4‐nitrophenyl)‐6‐(4‐n‐propoxyphenyl)hexa‐1,3,5‐triene, C21H21NO3, and (E,Z,E)‐1‐(4‐n‐butoxyphenyl)‐6‐(4‐nitrophenyl)hexa‐1,3,5‐triene, C22H23NO3, have been determined. Intermolecular N⋯O dipole interactions between the nitro groups are observed for the methoxy derivative, while for the ethoxy derivative, two adjacent molecules are linked at both ends through N⋯O dipole–dipole interactions between the N atom of the nitro group and the O atom of the ethoxy group to form a supramolecular ring‐like structure. In the crystal structures of the n‐propoxy and n‐butoxy derivatives, the shortest intermolecular distances are those between the two O atoms of the alkoxy groups. Thus, the nearest two molecules form an S‐shaped supramolecular dimer in these crystal structures. 相似文献
10.
Jose G. Trujillo‐Ferrara Rosa Luisa Santilln‐Baca Norberto Farfn‐García Itzia I. Padilla‐Martínez Efrn V. García‐Bez 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):o125-o128
The molecular and supramolecular structures of 2‐(1,3‐dioxo‐2,3,3a,4,7,7a‐hexahydro‐1H‐isoindol‐2‐yl)phenyl acetate, C16‐H15NO4, (I), and its para isomer, 4‐(1,3‐dioxo‐2,3,3a,4,7,7a‐hexahydro‐1H‐isoindol‐2‐yl)phenyl acetate, (II), are reported. The torsion angle between the succinimide and benzene rings depends on the position of the acetoxy substitution [89.7 (1) and 61.9 (1)° for (I) and (II), respectively]. The twist of the acetoxy group relative to the mean plane of the benzene ring is almost independent of the acetoxy position [66.0 (1) and 70.0 (1)°]. Packing interactions for both compounds include soft C—H⋯X (X = O and Ph) interactions, forming chains of centrosymmetric dimers and interlinked chains for (I) and (II), respectively. In addition, three perpendicular dipole C=O⋯C=O interactions contribute to the supramolecular structure of (II). 相似文献
11.
Shi‐Ping Yang Xi‐Bin Yu Ji‐Guang Huang Han‐Hong Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):o392-o393
The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetrahydro‐8,9‐dimethoxy‐2‐(1‐methylethenyl)‐[1]benzopyrano[3,4‐b]furo[2,3‐h][1]benzopyran‐6(6H)‐one oxime], C23H23NO6, confirms that the molecule has an approximately V‐shaped structure. One of the rings has a typical cyclohexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation. 相似文献
12.
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
13.
Antonio C. Doriguetto Marcelo H. Santos Javier A. Ellena Tanus J. Nagem 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1095-1097
The natural compound 5,10‐dihydroxy‐2,2‐dimethylpyrano[3,2‐b]xanthen‐6(2H)‐one (6‐deoxyjacareubin), C18H14O5, was isolated from leaves of Vismia latifolia (Guttiferae family). The compound has four six‐membered rings. The molecule has two planar benzenoid and one planar pyranoid ring, plus a pyranoid ring in a distorted chair conformation. The crystal is stabilized by one intra‐ and one intermolecular hydrogen bond. 相似文献
14.
Tarek Kassem Valrie Rolland Jean Martinez Marc Rolland 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1037-1039
We present the crystal and molecular structure of two key compounds of a new synthesis strategy for isomers of natural (2S,3R,4S)‐4‐hydroxyisoleucines, 2,3,5,6,7,8‐hexahydro‐3‐(1‐hydroxy‐1‐methyl‐2‐oxopropyl)‐6,8‐methano‐7,7,8a‐trimethyl‐5H‐1,4‐benzoxazin‐2‐one, C16H23NO4, and 2,3,5,6,7,8‐hexahydro‐3‐(1‐methyl‐2‐oxopropyl)‐6,8‐methano‐7,7,8a‐trimethyl‐5H‐1,4‐benzoxazin‐2‐one, C16H23NO3. A new optically pure chiral oxazinone auxiliary derived from (1R,2R,5R)‐2‐hydroxypinan‐3‐one was used. 相似文献
15.
Yi‐Ping Ye Hong‐Xiang Sun Yuan‐Jiang Pan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o397-o398
The title compound, 4‐methoxy‐2‐[(1S,2R,3S,4S,5R)‐3,4,5,6‐tetrahydro‐3,4,5‐trihydroxy‐6‐(hydroxymethyl)‐2H‐pyran‐2‐yl]‐α‐resorcylic acid δ‐lactone monohydrate, C14H16O9·H2O, is a C‐glucoside of 4‐O‐methylgallic acid which has antiasthmatic, antitussive, anti‐inflammatory, antifungal, anti‐HIV and antihepatotoxic activity. The molecule is composed of three six‐membered rings: an aromatic ring, a glucopyranose ring and an annellated δ‐lactone ring. The glucopyranose ring exhibits only small deviations from an ideal chair conformation. The annellated δ‐lactone ring possesses the expected half‐chair conformation. There is one intra‐ and six intermolecular hydrogen bonds which form an extensive hydrogen‐bonding network within the crystal. 相似文献
16.
Ning‐Hai Hu Yasuhiro Kiyota Katsuyuki Aoki 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1284-1286
In the title compound, 3‐[(3,4‐dihydro‐2‐methyl‐4‐oxopyrimidin‐5‐yl)methyl]‐5‐(2‐hydroxyethyl)‐4‐methylthiazolium hexafluorophosphate monohydrate, C12H16N3O2S+·PF6?·H2O, oxythiamine is a monovalent cation with a neutral oxopyrimidine ring. The molecule assumes the F conformation, which is a common form for thiamine but which is substantially different from the unusual V conformation found in the chloride and hydrochloride salts of oxythiamine. The anion‐bridging interaction, C—H?anion?pyrimidine, is emphasized as being important for stabilization of the F conformation. 相似文献
17.
Smriti Khera Michael D. Carducci Jian‐Qiao Gu Barbara N. Timmermann 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(11):o773-o775
The structure of an iridolactone isolated from Valeriana laxiflora was established as (4R,4aR,6S,7S,7aS)‐6‐hydroxy‐7‐hydroxymethyl‐4‐methylperhydrocyclopenta[c]pyran‐1‐one chloroform solvate, C10H16O4·CHCl3. The two rings are cis‐fused. The δ‐lactone ring adopts a slightly twisted half‐chair conformation with approximate planarity of the lactone group and the cyclopentane ring adopts an envelope conformation. The hydroxy group, the hydroxymethyl group and the methyl group all have β orientations. The absolute configuration was determined using anomalous dispersion data enhanced by the adventitious inclusion of a chloroform solvent molecule. Hydrogen bonding, crystal packing and ring conformations are discussed in detail. 相似文献
18.
J. Zukerman‐Schpector Mauricio Vega I. Caracelli Luiz C. Dias Anna M. A. P. Fernandes 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1089-1091
In 6‐methyl‐N‐(4‐nitrobenzoyl)‐5,6‐dihydropyridin‐2(1H)‐one, C13H12N2O4, (I), the piperidone ring is in a distorted half‐chair conformation. In 8‐methoxy‐3‐methyl‐N‐(4‐nitrobenzoyl)‐1,2,3,4,5,6,7,8‐octahydroisoquinoline‐1,6‐dione, C18H20N2O6, (II), the heterocyclic ring is in a slightly distorted half‐boat conformation, while the other six‐membered ring is in a distorted chair conformation. Compound (II) presents a strong intramolecular C—H?O hydrogen bond. In both (I) and (II), the molecules interact through C—H?O interactions. 相似文献
19.
Paul G. Jene James A. Ibers 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):705-707
The crystal structures of two elaborated‐porphyrin precursors have been determined. In the crystalline state, 2‐(1,3‐dithian‐2‐yl)benzaldehyde, C11H12OS2, has its dithiane ring in a slightly distorted chair conformation. The molecules pack in anti‐parallel chains. N‐{2‐[2‐(1,3‐Dioxan‐2‐yl)phenoxy]ethyl}phthalimide, C20H19NO5, is in a folded conformation. The dihedral angle between the phthalimide and phenyl planes is 80.07 (3)°. In the crystalline states, molecules stack on top of one another. 相似文献
20.
Zao‐Zao Qiu Xin‐Ping Hui Peng‐Fei Xu 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(8):o475-o476
The structure of the title compound, C22H24N2O9S2, is described. This compound consists of a sugar ring and a heterocyclic base linked unusually by an S atom. The sugar is in a 4C1 chair conformation and forms dihedral angles of 49.54 (4) and 33.42 (5)° with the thiadiazole and phenyl rings, respectively. The S atom occupies an equatorial position of the sugar ring and lies 1.807 (2) Å out of the corresponding mean plane. 相似文献