scholarly journals (2R,4R)-4-(2-Ethoxy-2-oxoethyl)-2,6,6-trimethyl–2-oxo-1,3,6,2λ5-dioxazaphosphocan-6-ium iodide

2012 ◽  
Vol 68 (6) ◽  
pp. o1596-o1596
Author(s):  
Bradford W. Fulfer ◽  
Frank R. Fronczek ◽  
Steven F. Watkins
Keyword(s):  
Title Compound ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Side Chain ◽  
Boat Conformation ◽  
Compound C ◽  
Chiral Centers

The title compound, C11H23NO5P+·I−, consists of an eight-membered cationic heterocyclic ring in a boat–chair conformation. The ring features a tetraalkylammonium N and a methylphosphonate P atom. A –CH2(CO)OC2H5 ester side chain at the C adjacent to oxygen produces two chiral centers at that substituted C atom and the P atom, both of which were determined to have absolute R,R configurations. A previously determined racemic bromide analog has exactly the same ring but with a –C15H31 side chain. In that structure, both chiral centers show the same relative R/S,R/S configurations, but the ring in the bromide analog is in a boat conformation.

scholarly journals 7′-Amino-1′H-spiro[cycloheptane-1,2′-pyrimido[4,5-d]pyrimidin]-4′(3′H)-one

2012 ◽  
Vol 68 (8) ◽  
pp. o2546-o2546
Author(s):  
Shu Chen ◽  
Daxin Shi ◽  
Mingxing Liu ◽  
Jiarong Li
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Compound C ◽  
Dimensional Network

The title compound, C12H17N5O, was obtained by cyclocondensation of 2,4-diaminopyrimidine-5-carbonitrile with cycloheptanone. The tetrahydropyrimidine ring has a distorted boat conformation and the cycloheptane ring adopts a chair conformation. In the crystal, molecules are linkedviaN—H...O and N—H...N hydrogen bonds generating a three-dimensional network.

6′′-Methoxy-1′-methyl-4′-phenylacenaphthene-1-spiro-2′-pyrrolidine-3′-spiro-3′′-chroman-2,4′′-dione

2007 ◽  
Vol 63 (11) ◽  
pp. o4412-o4412 ◽  
Author(s):  
T. Augustine ◽  
V. Ramkumar ◽  
S. Arul Antony ◽  
Charles. C. Kanakam
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Envelope Conformation ◽  
Compound C

In the crystal structure of the title compound, C31H25NO4, the five-membered heterocyclic ring is in an envelope conformation and the dihydropyrone ring is in a half-chair conformation.

scholarly journals (1R,4R,6S,7R)-5,5-Dibromo-1,4,8,8-tetramethyltricyclo[5.4.1.04,6]dodecan-12-one

2014 ◽  
Vol 70 (5) ◽  
pp. o526-o526 ◽  
Author(s):  
Mohamed Zaki ◽  
Ahmed Benharref ◽  
Jean-Claude Daran ◽  
Moha Berraho
Keyword(s):  
Title Compound ◽  
Chair Conformation ◽  
Membered Ring ◽  
The Other ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Cedrus Atlantica ◽  
Compound C ◽  
Independent Molecules

The title compound, C16H24Br2O, was synthesized from the reaction of β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from Atlas cedar (Cedrus atlantica). The asymmetric unit contains two independent molecules with similar conformations. Each molecule is built up from two fused seven-membered rings and an additional three-membered ring. In both molecules, one of the seven-membered rings has a chair conformation, whereas the other displays a screw-boat conformation.

(1R,4S,8R,12S,13S,14R,16S,19R)-14-Hydroxy-7,7-dimethyl-17-methylene-2,9,18-trioxo-3,10-dioxapentacyclo[14.2.1.01,13.04,12.08,12]nonadec-19-yl acetate

2007 ◽  
Vol 63 (11) ◽  
pp. o4439-o4439
Author(s):  
Hao Shi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Absolute Configuration ◽  
Title Compound ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules ◽  
The Absolute

The title compound, C22H26O8, prepared from the natural diterpenoid Macrocalyxin J, is built up from five fused rings. Cyclohenane ring A adopts a chair conformation, ring B exists in a screw-boat conformation and ring C adopts a boat conformation; the two five membered rings adopt envelope conformations. Two unique molecules are present in the asymmetric unit; both independent molecules have the same absolute configuration, the absolute configuration being deduced from the chirality of Macrocalyxin A, which was isolated from the same plant (i.e. Rabdosia macrocalyx) as Macrocalyxin J. The crystal structure displays intermolecular O—H...O hydrogen bonds.

scholarly journals Crystal structure of 3-(3-oxo-2,3,4,4a,5,6-hexahydrobenzo[h]cinnolin-2-yl)propionic acid

2014 ◽  
Vol 70 (10) ◽  
pp. o1088-o1089
Author(s):  
Fiorella Meneghetti ◽  
Daniela Masciocchi ◽  
Arianna Gelain ◽  
Stefania Villa
Keyword(s):  
Chair Conformation ◽  
Membered Ring ◽  
Side Chain ◽  
Boat Conformation ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Compound C ◽  
Centroid Distance ◽  
Independent Molecules ◽  
Twisted Boat

The asymmetric unit of the title compound, C15H16N2O3, contains two independent molecules, which present a different conformation of the carboxylic acid side chain [C—C—C—OH torsion angles = 65.3 (7) and −170.1 (5)°]. In both molecules, the dihydropyridazinone ring adopts a geometry intermediate between a twisted-boat and a half-chair conformation, while the central six-membered ring is almost in a half-boat conformation. In the crystal, molecules are linked by O—H...Ok(k = ketone) hydrogen bonds, generating [01-1] chains. Aromatic π–π stacking contacts between the benzene and the dihydropyridazinone rings [centroid–centroid distance [3.879 (9) Å] are also observed.

rac-4-Methoxy-6-phenyl-5,6-dihydro-2-pyrone

2007 ◽  
Vol 63 (3) ◽  
pp. o1274-o1275
Author(s):  
C. A. De Simone ◽  
L. C. de Souza ◽  
D. de O. Imbroisi ◽  
J. F. T. Oliveira ◽  
M. A. Pereira
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Compound C ◽  
Dimensional Network

In the title compound, C12H12O3, the heterocyclic ring adopts a half-chair conformation. C–H...O hydrogen bonds form a three-dimensional network.

scholarly journals 1-Cyclohexyl-6,7-dimethoxy-1,4-dihydronaphthalene

2014 ◽  
Vol 70 (6) ◽  
pp. o671-o671 ◽  
Author(s):  
Shao-Yuan Chen ◽  
Ya-Ping Zhang ◽  
Bing Huang ◽  
Jia-Jun Yu ◽  
Wei-Yong Shi
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Chair Conformation ◽  
Ficus Carica ◽  
Cyclohexane Ring ◽  
Boat Conformation ◽  
Axis Direction ◽  
Compound C ◽  
Supramolecular Chains

The title compound, C18H24O2, was isolated from the leaves extract ofFicus caricaL. The cyclohexane ring displays a chair conformation whereas the cyclohexa-1,4-diene ring adopts a flattened boat conformation with methyl C atoms at the prow and stern. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains propagated along theb-axis direction.

scholarly journals (2S,4R)-2-[(1R)-1-(4-Bromophenyl)-2-nitroethyl]-4-ethylcyclohexanone

2013 ◽  
Vol 69 (2) ◽  
pp. o263-o263 ◽  
Author(s):  
Chi-Xiao Zhang ◽  
Yan-Peng Zhang ◽  
Ai-Bao Xia
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Chair Conformation ◽  
Cyclohexane Ring ◽  
Axis Direction ◽  
Compound C ◽  
Chiral Centers

The crystal structure of the title compound, C16H20BrNO3, contains three chiral centers in the configuration 1R,2S,6R. The cyclohexane ring is in a chair conformation. In the crystal, molecules are linked by weak C—H...O interactions, forming chains along thea-axis direction.

scholarly journals (2Z)-2-Benzylidene-4-n-butyl-3,4-dihydro-2H-1,4-benzothiazin-3-one

2014 ◽  
Vol 70 (6) ◽  
pp. o686-o686 ◽  
Author(s):  
Nada Kheira Sebbar ◽  
Mohammed El Fal ◽  
El Mokhtar Essassi ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Benzene Ring ◽  
Dihedral Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
Heterocyclic Ring ◽  
Boat Conformation ◽  
Compound C ◽  
The Mean ◽  
Supramolecular Chains

In the title compound, C19H19NOS, the six-membered heterocyclic ring of the benzothiazine fragment exhibits a screw boat conformation. The plane of the fused benzene ring makes a dihedral angle of 72.38 (12)° with that of the terminal phenyl ring, and is nearly perpendicular to the mean plane formed by the atoms through then-butyl chain, as indicated by the dihedral angle of 88.1 (2)°. In the crystal, molecules are linked by C—H...O interactions to form supramolecular chains along [110].

scholarly journals (1β,2α,3α,7α,11α,13β)-1,3,7,11-Tetraacetoxy-2,13-bis(benzyloxy)-21-methyl-19,21-secohetisan-19-al hemihydrate

2009 ◽  
Vol 65 (6) ◽  
pp. o1432-o1432 ◽  
Author(s):  
Feng-Zheng Chen ◽  
Qing-Xiang Xiang ◽  
Yuan-Qin Zhang ◽  
Jun-Ru Xiong
Keyword(s):  
Crystal Structure ◽  
Organic Molecule ◽  
Chair Conformation ◽  
Heterocyclic Ring ◽  
Membered Ring ◽  
Boat Conformation ◽  
Solvent Water ◽  
Compound C ◽  
Benzene Rings ◽  
Carbocyclic Rings

In the crystal structure of the title compound, C43H46NO13·0.5H2O, the molecule assumes a U-shaped conformation, the terminal benzene rings being approximately parallel and partially overlapped with each other. The molecule contains eight alicyclic and heterocyclic rings. The cyclohexane rings adopt chair conformations, the other three six-membered carbocyclic rings form a bicyclo[2.2.2]octane system with a boat conformation for each six-membered ring, the six-membered heterocyclic ring has a chair conformation and both of the five-membered rings have envelope conformations. The solvent water molecule links with the organic moleculeviaclassic O—H...O and weak C—H...O hydrogen bonding in the crystal structure.

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