Crystal Structure and Chirality of the Ansamycin Antibiotic Actamycin

1991 ◽  
Vol 44 (5) ◽  
pp. 655 ◽  
Author(s):  
TW Hambley ◽  
V Parthasarathi ◽  
RW Rickards ◽  
GB Robertson
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Double Bond ◽  
Least Squares ◽  
Absolute Configuration ◽  
Torsion Angle ◽  
Title Compound ◽  
Intermolecular Hydrogen Bonding ◽  
Triclinic Space Group ◽  
Relative Stereochemistry

The structure of the title compound has been determined from diffractometer data recorded, initially, at 294 K and, subsequently, at 168 K. Crystals are triclinic, space group P1 with (168 K values in square brackets) a 16.080(2) [15.934(2)], b 15.958(2) [15.880(2)], c 8.443(2)Ǻ [8.233(1)Ǻ], α 85.55(1) [86.04(1)],β 82.65(1) [82.56(1)],γ 85.00(1)° [84.73(1)°], and contain two actamycin and two solvent ( tetrahydrofuran ) molecules in the asymmetric scattering unit. The structure was solved with DIRDIF and refined by block-diagonal least-squares analysis (of 168 K data) to R 0.049 ( wR 0.069) for 5640 reflections and 940 refined parameters. Molecules of actamycin (30-dechloro-2-demethyl-30-hydroxynaphthomycin A) exhibit the same relative stereochemistry (8S*,9S*,15S*,18S*,19S*,20S*) and double-bond configuration (2Z,4Z,6E,12E,16E,21E) as reported for crystalline 25-O-methylnaphthomycin A iminomethyl ether but are quite differently conformed. The two crystallographically inequivalent actamycin molecules in the present structure also exhibit substantial conformational (torsion angle) differences due, apparently, to the effects of intermolecular hydrogen bonding. Consideration of chiroptical data defines the absolute configuration of actamycin as 8S,9S,15S,18S,19S,20S and the helicity as P, as in naphthomycin A.

(2R,3S,4S,5R)-4-Hydroxy-3-iodo-5-methyltetrahydro-2-furylmethyl benzoate

2000 ◽  
Vol 57 (1) ◽  
pp. o58-o60
Author(s):  
Sean P. Bew ◽  
Mark E. Light ◽  
Michael B. Hursthouse ◽  
David W. Knight ◽  
Robert J. Middleton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Structure Determination ◽  
Title Compound ◽  
Crystal Structure Determination ◽  
Intermolecular Hydrogen Bonding ◽  
Compound C ◽  
Relative Stereochemistry

The crystal structure determination of the title compound, C13H15IO4, has allowed the relative stereochemistry between the tetrasubstituted C atoms on the tetrahydrofuran moiety to be confirmed. The title compound is a precursor of the ionophoric antibiotic Aplasmomycin. The compound is involved in both intra- and intermolecular hydrogen bonding, the latter link the molecules into chains running along thebaxis.

scholarly journals Crystal structure of (E)-3-(5-bromo-2-hydroxyphenyl)acrylaldehyde

2014 ◽  
Vol 70 (11) ◽  
pp. o1219-o1220
Author(s):  
Sung-Gon Kim
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Torsion Angle ◽  
Title Compound ◽  
Three Dimensional ◽  
Maximum Deviation ◽  
Supramolecular Network ◽  
Compound C

The title compound, C9H7BrO2, displays atransconfiguration with respect to the C=C double bond and is essentially planar [maximum deviation from the least-squares plane through all non-H atoms = 0.056 (4) Å]. The vinylaldehyde group adopts an extended conformation wih a C—C—C—C torsion angle of 179.7 (4)°. In the crystal, molecules are linked by classical O—H...O and weak C—H...O hydrogen bonds into a three-dimensional supramolecular network.

scholarly journals Crystal structure of 5-benzoyl-2,4-diphenyl-4,5-dihydrofuran-3-carbonitrile

2015 ◽  
Vol 71 (9) ◽  
pp. o663-o664
Author(s):  
V. Rajni Swamy ◽  
R.V. Krishnakumar ◽  
S. Sivakumar ◽  
N. Srinivasan ◽  
R. Ranjith Kumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Lattice ◽  
Torsion Angle ◽  
Title Compound ◽  
Intermolecular Hydrogen Bonding ◽  
Compound C ◽  
Benzoyl Group ◽  
Graph Set

In the title compound, C24H17NO2, the carbonyl O atom of the benzoyl group isciswith respect to the furanyl O atom, and the associated O—C—C—O torsion angle is 4.62 (19)°. The puckering of the dihydrofuran ring is close to twisted (4T5), with parametersQ= 0.1856 (16) Å and φ = 313.5 (5)°. Molecules are interconnectedviaa C—H...N and a C—H...O hydrogen bond, leading to layers parallel to the (200) plane and characterized byR44(28) andR44(36) graph-set motifs. The furan O atom does not participate in intermolecular hydrogen bonding. The crystal lattice encompasses a solvent-accessible void of 24.7 (8) Å3.

scholarly journals Crystal structure of (3E)-3-(2,4-dinitrophenoxymethyl)-4-phenylbut-3-en-2-one

2014 ◽  
Vol 70 (9) ◽  
pp. o1051-o1052 ◽  
Author(s):  
Ignez Caracelli ◽  
Stella H. Maganhi ◽  
Paulo J. S. Moran ◽  
Bruno R. S. de Paula ◽  
Felix N. Delling ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Nitro Group ◽  
Benzene Ring ◽  
Torsion Angle ◽  
Title Compound ◽  
Phenyl Ring ◽  
Aromatic Rings ◽  
Compound C ◽  
The One

In the title compound, C17H14N2O6, the conformation about the C=C double bond [1.345 (2) Å] isE, with the ketone moiety almost coplanar [C—C—C—C torsion angle = 9.5 (2)°] along with the phenyl ring [C—C—C—C = 5.9 (2)°]. The aromatic rings are almost perpendicular to each other [dihedral angle = 86.66 (7)°]. The 4-nitro moiety is approximately coplanar with the benzene ring to which it is attached [O—N—C—C = 4.2 (2)°], whereas the one in theorthoposition is twisted [O—N—C—C = 138.28 (13)°]. The molecules associateviaC—H...O interactions, involving both O atoms from the 2-nitro group, to form a helical supramolecular chain along [010]. Nitro–nitro N...O interactions [2.8461 (19) Å] connect the chains into layers that stack along [001].

scholarly journals Crystal structure of a trigonal polymorph of aquadioxidobis(pentane-2,4-dionato-κ2 O,O′)uranium(VI)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Alejandro Hernandez ◽  
Indranil Chakraborty ◽  
Gabriela Ortega ◽  
Christopher J. Dares
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Water Molecule ◽  
Equatorial Plane ◽  
Title Compound ◽  
Uranium Atom ◽  
Intermolecular Hydrogen Bonding ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Acta Cryst

The title compound, [UO2(acac)2(H2O)] consists of a uranyl(VI) unit ([O=U=O]2+) coordinated to two monoanionic acetylacetonate (acac, C5H7O2) ligands and one water molecule. The asymmetric unit includes a one-half of a uranium atom, one oxido ion, one-half of a water molecule and one acac ligand. The coordination about the uranium atom is distorted pentagonal–bipyramidal. The acac ligands and Ow atom comprise the equatorial plane, while the uranyl O atoms occupy the axial positions. Intermolecular hydrogen bonding between complexes results in the formation of two-dimensional hexagonal void channels along the c-axis direction with a diameter of 6.7 Å. The monoclinic (P21/c space group) polymorph was reported by Alcock & Flanders [(1987). Acta Cryst. C43, 1480–1483].

Crystal structure of (Z)-Cembr-4-ene-15,19,20-triol

1977 ◽  
Vol 30 (12) ◽  
pp. 2723 ◽  
Author(s):  
EN Maslen ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Single Crystal ◽  
Least Squares ◽  
Structure Determination ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Relative Configuration ◽  
Macrocyclic Ring ◽  
X Ray

The crystal structure of the title compound, CZOH3803 [compound (1) in ref.'], has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.045 for 954 'observed' reflections. Crystals are monoclinic, P2', a 9.281(2), b 17.798(6), c 6.417(1) A, B 93.81(3)", Z 2. The structure determination establishes the relative configuration of the chiral centres within the 14-membered macrocyclic ring and shows the double bond to have the unusual (Z) configuration.

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.

(13bR,13cS)-rel-11b,11c-Diphenyl-6,11-dihydro-1H,3H,4H,13H-2-oxa-3a,4a,5a,11a,12a,13a-hexaazabenz[f]indeno[2,1,8-ija]naphth[2,3-f]azulene-4,6,11,13-tetrone chloroform solvate

2006 ◽  
Vol 62 (7) ◽  
pp. o2945-o2946
Author(s):  
Sheng-li Hu ◽  
Hui-Zhen Guo ◽  
Neng-Fang She
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Title Compound ◽  
Intermolecular Hydrogen Bonding ◽  
Molecular Tweezers ◽  
Compound C ◽  
Important Intermediate

The crystal structure of the title compound, C28H22N6O5·CHCl3, an important intermediate for molecular tweezers, shows intermolecular hydrogen bonding.

scholarly journals Quinine dihydrochloride hemihydrate

IUCrData ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Grace I. Anderson ◽  
Sophia Bellia ◽  
Matthias Zeller ◽  
Patrick C. Hillesheim ◽  
Arsalan Mirjafari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Double Bond ◽  
Long Range ◽  
Title Compound ◽  
Asymmetric Unit ◽  
Hydrogen Atoms ◽  
Non Covalent Interactions ◽  
Long Range Ordering ◽  
Covalent Interactions

Numerous non-covalent interactions link together discrete molecules in the crystal structure of the title compound, 2C20H26N2O2 2+·4Cl−·H2O {systematic name: 4-[(5-ethenyl-1-azoniabicyclo[2.2.2]octan-2-yl)(hydroxy)methyl]-6-methoxyquinolin-1-ium dichloride hemihydrate}. A combination of hydrogen bonding between acidic H atoms and the anions in the asymmetric unit forms a portion of the observed hydrogen-bonded network. π–π interactions between the aromatic portions of the cation appear to play a role in the formation of the long-range ordering. One ethylene double bond was found to be disordered. The disorder extends to the neighboring carbon and hydrogen atoms.

(+)-N-[(R)-1-(2-Hydroxy-5-methylphenyl)propyl]-N-[(R)-2-methyl-1-phenylpropyl]ammonium chloride

2006 ◽  
Vol 62 (7) ◽  
pp. o2622-o2624 ◽  
Author(s):  
Xiao-Feng Yang ◽  
Da-Qi Wang ◽  
Guang-You Zhang ◽  
Takuji Hirose
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Ammonium Chloride ◽  
Absolute Configuration ◽  
Title Compound ◽  
Condensation Reaction ◽  
Compound C ◽  
The Absolute ◽  
Phenol Ring

The title compound, C20H28NO+·Cl−, was synthesized by a condensation reaction. The absolute configuration of the new stereogenic centre (the C atom between the N atom and the phenol ring) was determined as R. The crystal structure is stabilized through N—H...Cl and O—H...Cl hydrogen bonds and intramolecular N—H...O hydrogen bonding.

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