The molecular and crystal structure of 4,4-dimethyl-6,6-diphenyl-tetrahydro-2H-pyran-2-one

1989 ◽  
Vol 54 (6) ◽  
pp. 1661-1665
Author(s):  
Jiří Novotný ◽  
Jan Ondráček ◽  
Marián Schwarz ◽  
Bohumil Kratochvíl
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Least Squares ◽  
Heterocyclic Compound ◽  
Least Squares Method ◽  
Lactone Ring ◽  
Direct Methods ◽  
Molecular And Crystal Structure ◽  
Boat Conformation ◽  
C Nmr

The molecular and crystal structure of 4,4-dimethyl-6,6-diphenyl-tetrahydro-2H-pyran-2-one was solved by direct methods and anisotropically refined by the least squares method. The final R-factor value was 0.065 for 2 181 observed reflections (I > 1.96σ (I)) and 272 refined parameters. The symmetry of the structure corresponds to the P21/c space group with lattice parameters a = 11.207(2), b = 8.168(1), c = 16.896(3) Å, β = 90.05(1)°. The unit cell contains four formula units. A lactone structure was found for this geminally substituted heterocyclic compound and was also demonstrated by 1H and 13C NMR spectroscopy. The lactone ring assumes the boat conformation.

Conformation Dependent Cyclizations of 1,3,3,5-Tetraphenylpentane-1,5-dione

1992 ◽  
Vol 57 (11) ◽  
pp. 2383-2399 ◽  
Author(s):  
Pavel Šebek ◽  
Jiří Novotný ◽  
Bohumil Kratochvíl ◽  
Marián Schwarz ◽  
Josef Kuthan
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Direct Methods ◽  
Lattice Parameters ◽  
Molecular And Crystal Structure ◽  
Complex Hydrides ◽  
Pyran Derivative ◽  
Phenylmagnesium Bromide

The molecular and crystal structure of 1,3,3,5-tetraphenylpentane-1,5-dione (I) obtained from direct methods and anisotropically refined by the least-squares method shows that the two 3,3-phenyl groups force the molecule into a conformation suitable for formation of cyclic products and intermediates. Compound I crystallizes in P1 group with lattice parameters a = 8.444(1), b = 10.195(2), c = 14.618(2) Å, α = 75.52(2)°, β = 73.22(1)°, γ = 65.47(1)°. Photochemically and thermally found was the system I ↔ II. The reaction of 1,5-dione I with phenylmagnesium bromide gives the 2,3-dihydropyran derivative III, whereas complex hydrides give a mixture of IV and VI. On treatment with magnesium, the diketone I gives diol VIII. Chlorine (Cl2) reacts with compound I to give the mono-, di-, and tetrachloro derivatives XII, XIII, and XIV, respectively. Bromine (Br2) produces 3,5-dibromo-4H-pyran derivative XVIII, whereas I2 only catalyzes the formation of 4H-pyran V. The formylation of dione I with dimethylformamide and POCl3 gives the 4H-pyran-3-carbaldehyde XX. Probable mechanisms of the reactions investigated and the stereochemistry of compounds VI, VIII, XIII, and XIV are discussed.

The Bayer-Villiger oxidation of diamantanone and the structure of 11-oxo-10-oxapentacyclo[7,4,1,14,13,02,7,06,12]-pentadecane

1989 ◽  
Vol 54 (12) ◽  
pp. 3260-3266 ◽  
Author(s):  
Jan Ondráček ◽  
Josef Janků ◽  
Jiří Novotný ◽  
Luděk Vodička ◽  
László Csordás ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
General Position ◽  
Direct Methods ◽  
Inverse Image ◽  
Unit Cell ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
C Nmr ◽  
Villiger Oxidation

The studied substance was prepared by the Bayer-Villiger oxidation of diamantanone and identified by 1H and 13C NMR spectroscopy. The structure of the compound was solved by direct methods and refined to the value R = 0.052 for 845 observed reflections (I > 1.96σ(I)). The substance crystallizes in the orthorhombic space group Pnnm; a = 23.595(4), b = 10.284(2), c = 6.676(1) Å. The unit cell of the crystal structure of 11-oxo-10-oxapentacyclo[7,4,1,14,13,02,7,06,12]pentadecane contains four ordered and two disordered molecules. The disordered molecule is described by averaging the image of the ordered molecule and its inverse image. Thus, the unit cell contains 6 formula units (part of the atoms have fractional occupation factors) even though the multiplicity of the general position in the Pnnm group is 8.

The crystal structure of potassium 1-(N,N-diphenylhydrazono)-2,4,6-trinitrobenzenide

1983 ◽  
Vol 61 (12) ◽  
pp. 2735-2739 ◽  
Author(s):  
Ramanathan Gopal ◽  
Beverly E. Robertson ◽  
John A. Weil
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Least Squares ◽  
Diffraction Data ◽  
Direct Methods ◽  
Boat Conformation ◽  
Full Matrix ◽  
Short Contact ◽  
Oxygen Atoms

Crystals of potassium 1-(N,N-diphenylhydrazono)-2,4,6-trinitrobenzenide, C18H12N5O6K, are monoclinic, P21/c, a = 9.871(2), b = 12.940(3), c = 16.754(4) Å, β = 118.31(1)°, Z = 4, T = 22 °C. Diffraction data were collected on a modified Picker FASC-1 diffractometer. The structure was solved by direct methods and refined by full-matrix least-squares to R = Rw = 0.056 using the 2627 independent reflections with [Formula: see text]. The benzenide ring shows a significant puckering toward the boat conformation. Some important canonical structures contributing to the average geometry of the molecule are discussed. The bonding sphere of the K+ cation contains all of the oxygen atoms and the hydrazine nitrogen atom bonded to the trinitrobenzenide group. Two phenyl carbon atoms also have short contact distances to the cation.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

The crystal structure of arsenic telluroxide AsTe0.5O2

1993 ◽  
Vol 205 (1) ◽  
Author(s):  
A. C. Stergiou
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Single Crystals ◽  
Direct Methods ◽  
Anomalous Dispersion ◽  
Thermal Parameters ◽  
Trigonal Prism ◽  
Population Parameter ◽  
Full Matrix

AbstractSingle crystals of AsTeSolution of the structure was essentialy effected by direct methods combined with successive Fourier syntheses. The positional and anisotropic thermal parameters were refined by full-matrix least-squares calculations. Absorption and anomalous dispersion corrections were applied to all atoms. The finalThe As atom is coordinated by six O atoms forming a right trigonal prism. The Te atom site is partially occupied by Te atoms with a population parameter 0.5 and surrounded by six O atoms also forming a right trigonal prism. The structure looks like that of NiAs. Each of the AsO

scholarly journals Three-Dimensional Supramolecular Network Directed by Intermolecular Interactions in [Pb2(dmp)2(hfacac)4]

2009 ◽  
Vol 6 (4) ◽  
pp. 1085-1090
Author(s):  
Farzin Marandi ◽  
Lotfali Saghatforoush ◽  
Hossein Farzaneh
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
H Nmr ◽  
Noncovalent Bond ◽  
Donor And Acceptor ◽  
Anionic Ligands ◽  
C Nmr

To investigate the interactions between noncovalent bond donor and acceptor giving rise to three dimensional networks, compound [Pb2(dmp)2(hfacac)2] (1) (dmp = 2,9-dimethyl-1,10-henanthroline and Hhfacac = hexafluoroacetylacetonate) has been prepared and characterized by elemental analysis, IR,1H NMR, and13C NMR spectroscopy and its crystal structures was investigated. The single crystal structure show the coordination number of Pb(II) to be eight with twoN-donor atoms from a “dmp” ligand and sixO-donors from the anionic ligands. The supramolecular structure of 1 is realized by weak directional C–H∙∙∙O–C, C–F∙∙∙F–C andπ–πstacking interactions.

1,2,6-Thiadiazin-3,5(2H,6H)-dione 1,1-dioxide derivatives: crystal structure, physico-chemical and biological properties

1987 ◽  
Vol 65 (2) ◽  
pp. 298-302 ◽  
Author(s):  
Pilar Goya ◽  
Rosa Nieves ◽  
Carmen Ochoa ◽  
Carmen Rodellas ◽  
Martín Martinez-Ripoll ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Biological Properties ◽  
Anomalous Variation ◽  
Physico Chemical ◽  
C Nmr

Crystal structure, 1H and 13C nmr spectroscopy and pKa measurements of 1,2,6-thiadiazin-3,5(2H,6H)-dione derivatives related with phenylbutazone are reported. An anomalous variation in the pKa values of compounds 1,2, and 3 has been observed. Antiinflammatory, analgesic, and antipyretic activities of these compounds have been evaluated.

The crystal structure of kogarkoite, Na3SO4F

1980 ◽  
Vol 43 (330) ◽  
pp. 753-759 ◽  
Author(s):  
L. Fanfani ◽  
G. Giuseppetti ◽  
C. Tadini ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Thermal Parameters ◽  
Cell Content ◽  
Space Group ◽  
X Ray ◽  
Structural Relationships ◽  
Automatic Diffractometer ◽  
Monoclinic Cell

SummaryThe crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

Structural studies of organoboron compounds. XLIII. 4-[(1-Hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene

1991 ◽  
Vol 69 (3) ◽  
pp. 545-549 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Ute Schumacher ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Key Words ◽  
Hydroxamic Acid ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths ◽  
Acid Chelate

The reaction of N′-hydroxy-N-[(1-hydroxycyclohexyl)methyl]benzamide and diphenylborinic anhydride gives 4-[(1-hydroxycyclohexyl)methyl]-2,2,5-triphenyl-1,3-dioxa-4-azonia-2-borata-4-cyclopentene in nearly quantitative yield. Crystals of the product are monoclinic, a = 9.9117(6), b = 13.308(1), c = 17.339(2) Ǻ, β = 99.420(7)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.047 for 2423 reflections with I > 3σ(I). The molecule has a normal five-membered hydroxamic acid chelate structure, the BONCO ring having a B-envelope conformation. Bond lengths (corrected for libration) (N)O—B = 1.535(3), (C)O—B = 1.569(3), C—B = 1.603(3) and 1.601(3) Ǻ are normal for this type of complex. Key words: organoboron compound, boron compound, crystal structure.

7α-Acetoxydihydronomilin: isolation, spectra, and crystal structure

1978 ◽  
Vol 56 (7) ◽  
pp. 1020-1025 ◽  
Author(s):  
Farid R. Ahmed ◽  
Angs Ng ◽  
Alex G. Fallis
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Furan Ring ◽  
Lactone Ring ◽  
Direct Method ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray ◽  
Twist Boat

Methanol extraction of the ground seeds of Uncaria Gambier Roxb. followed by chromatography afforded a crystalline C30H38O10 terpene. This has been shown by X-ray analysis to be 7α-acetoxydihydronomilin. The crystals are orthorhombic, P212121, a = 13.158(2), b = 17.092(2), c = 12.689(2) Å, Z = 4, dx = 1.300, do = 1.300 g cm−3. The structure has been determined by the direct method and Fourier syntheses, and refined by block-diagonal least-squares to R = 0.042 for 2621 observed reflexions. The molecule contains a seven-membered lactone ring A, three six-membered rings B, C, D, a three-membered ring E, a furan ring F, and two acetate groups. A and B are chair, C is twist-boat, D is 1,3-diplanar, while E and F are planar. The A/B, A/C, C/D junctions are trans, D/E is cis, and F is linked to D by an equatorial C—C bond. The two acetate groups are in axial positions on A and B and are cis to each other. The O atom forming the apex of the three-membered ring is wedged between two H atoms and their parent C atoms at short intramolecular distances O … H = 2.28(2) and 2.28(3), and O … C = 2.623(3) and 2.668(4) Å. No intermolecular hydrogen bonding is indicated.

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