Synthetic plant growth regulators. V. The synthesis and crystal structure of a hybrid gibberellin-helminthosporic acid

1980 ◽  
Vol 33 (5) ◽  
pp. 1061 ◽  
Author(s):  
JV Turner ◽  
BF Anderson ◽  
LN Mander
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Carboxylic Acid ◽  
Standard Procedure ◽  
Direct Methods ◽  
Detailed Comparison ◽  
Synthesis And Crystal Structure ◽  
Full Matrix ◽  
Cyclopropyl Ketone ◽  
R Value

(3aRS,4RS,6RS,8aSR)-5-Methyleneoctahydro-4H-3a,6-methanoazulene-4-carboxylic acid (7) has been synthesized and a detailed comparison made between its molecular structure and that of gibberellic acid (4). Indane-5-carboxylic acid (8) was converted by an alternating sequence of reduction and isomerization into the hydrindene acid (11). The diazomethyl ketone derived from (11) was transformed to cyclopropyl ketone (12) which was reduced by Li/NH3 with stereochemical inversion at the β-carbon to give a 1:3 mixture of ketones (13) and (14) respectively. Ketone (14) was then converted into the title acid (7) by a standard procedure. ��� Molecules of (7) crystallize in space group P2/c with a 7.782(1), b 11.055(1), c 14.559(3) Ǻ, β 116.05(1)°. The structure was solved by direct methods and refined by full-matrix least squares to a final R value of 0.053.

Reaction of N,N′-dihydroxy-.N,N′-dimethylmethanediamine with phenylboronic acid and the crystal and molecular structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine

1989 ◽  
Vol 67 (11) ◽  
pp. 1959-1963 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Exact Formula ◽  
Full Matrix ◽  
Space Group ◽  
Hydrogen Bonded

The reaction of N,N′-dihydroxy-N,N′-dimethylmethanediamine with phenylboronic acid leads to the product 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane rather than the expected product 1,5-dimethyl-3-phenyl-1,5-diaza-2,4-dioxa-3-boracyclohexane. The structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine has been determined and is discussed in terms of its reaction with PhB(OH)2. Crystals of N,N′-dihydroxy-N,N′-dimethylmethanediamine are tetragonal, a = 8.5346(3), c = 8.4178(7) Å, Z = 4, space group P421c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.036 and Rw of 0.038 for 333 reflections with I ≥ 3σ(I). The structure consists of hydrogen-bonded dimers having exact [Formula: see text] symmetry. Keywords: N,N′-dihydroxy-N,N′-dimethylmethanediamine, crystal structure.

The methylgallium-2-carboxylatobenzimidazolato hexamer, [MeGa·C8H4N2O2]6·C6H6·(Me2C6H4)2; synthesis and X-ray crystal structure

1999 ◽  
Vol 77 (4) ◽  
pp. 434-438 ◽  
Author(s):  
Steven J Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Room Temperature ◽  
Direct Methods ◽  
Membered Ring ◽  
Coordination Geometry ◽  
Temperature Reaction ◽  
Full Matrix ◽  
X Ray ◽  
Solvent Molecules

The room-temperature reaction of Me3Ga with benzimidazole 2-carboxylic acid in xylene solvent has yielded a novel crystalline hexameric gallium compound with "MeGa" moieties bridged by the doubly depronotated ligand precursor. Crystals of [MeGa(4,5-benzimidazolato-2-carboxylato)]6·(C6H6)·(m-Me2C6H4)2 are monoclinic, a = 18.091(2), b = 17.094(2), c = 13.2215(5) Å, Z = 2, space group C2/m. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R (F, I [Formula: see text] 3σ(I)) = 0.064 (Rw (F2, all data) = 0.134). The hexameric Ga complex contains a six-membered ring of Ga atoms, bridged by the benzimidazolate ligands with the benzo rings projecting alternately above and below the Ga plane, thus forming a ball-shaped molecule. The complex could have ideal D3d symmetry, but it contains an encapsulated molecule of benzene, which distorts the regularity of the Ga6 hexagon, and reduces the symmetry of the complex to the crystallographically observed C2h. The coordination geometry at each of the two independent GaO2N2C centres approximates a trigonal bipyramid, with a N2C trigonal plane, and the O atoms above and below; average dimensions are Ga-O = 2.176(2), Ga-N = 1.973(3), Ga-C = 1.927(5) Å, O-Ga-O = 165°. The unit cell also contains four m-xylene solvent molecules (outside the molecular cage).Key words: gallium, crystal structure, benzene intercalate, benzimidazolecarboxylic acid.

Crystal and molecular structure of L-prolinatodiphenylboron

1977 ◽  
Vol 55 (6) ◽  
pp. 958-965 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Conformational Disorder ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of L-prolinatodiphenylboron are monoclinic, a = 5.9427(5), b = 14.4633(7), c = 8.9654(4) Å, β = 98.423(8)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.037 and Rw of 0.053 for 1477 reflections with I ≥ 3σ(I). The proline ring exhibits conformational disorder. The crystal structure consists of discrete molecules linked by N—H … O hydrogen bonds (N … O = 2.893(3) Å) along the short a axis. Intramolecular N—B coordination occurs to form a system of two fused five-membered rings. Bond lengths (corrected for libration) are: N—B, 1.630(3), O—B, 1.529(3), O—C, 1.219(3) and 1.300(3), N—C, 1.506(3) and 1.507(3), C(sp3)–C(sp3), 1.525(4), C(sp2)—C(sp3), 1.517(3), and mean C—C(phenyl), 1.394 Å.

Structural studies of organoboron compounds. XXII. Preparation and crystal and molecular structure of tetramethylammonium-2,4,6,6-tetraphenyl-1,3,5-trioxa-2,4- dibora-6-boratacyclohexane

1985 ◽  
Vol 63 (12) ◽  
pp. 3516-3520 ◽  
Author(s):  
W. Kliegel ◽  
H.-W. Motzkus ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Physical Properties ◽  
Crystal And Molecular Structure ◽  
Structural Parameters ◽  
Direct Methods ◽  
Maximum Deviation ◽  
Structural Studies ◽  
Full Matrix ◽  
The Mean

Details of the preparation and physical properties of (Me4N)+ (Ph4B3O3)− are given. Crystals of tetramethylammonium 2,4,6,6-tetraphenyl-1,3,5-trioxa-2,4-dibora-6-boratacyclohexane are orthorhombic, a = 18.130(2), b = 11.9745(7), c = 12.5187(5) Å, Z = 4, space group Pna21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.056 and Rw = 0.064 for 1460 reflections with I ≥ 2σ(I). The crystal structure consists of discrete tetramethylammonium cations and tetraphenylboroxinate anions, the first such anion to be structurally characterized. The six-membered B3O3 ring is significantly non-planar, having a flattened O(1)-envelope conformation (maximum deviation from the mean plane = 0.074(4) Å for O(1)). The boroxine ring in the anion shows significant deviations from the D3h symmetry observed for neutral boroxines. Important mean structural parameters: B(sp3)—O = 1.494(2), B(sp2)—O[B(sp3)] = 1.320(9), B(sp2)—O[B(sp2)] = 1.389(3) Å, O—B(sp3)—O = 110.5(5), O—B(sp2)—O = 121.7(6), B(sp2)—O—B(sp2) = 118.9(5), and B(sp3)—O—B(sp2) = 122.9(1)°.

Crystal and molecular structure of 8,8-dimethyl-3,5-diphenyl-2,4,6-trioxa-1-azonia-3-bora-5-boranatabicyclo[3.3.0]octane

1976 ◽  
Vol 54 (20) ◽  
pp. 3142-3151 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
H. Becker
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Boron Atom ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
The Other ◽  
Full Matrix ◽  
Atom Bond ◽  
Tetrahedral Boron

Crystals of 8,8-dimethyl-3,5-diphenyl-2,4,6-trioxa-1-azonia-3-bora-5-boranatabicyclo[3.3.0]-octane are monoclinic, a = 22.323(1), b = 9.555(1), c = 16.0027(6) Å, β = 109.055(4)°, Z = 8, space group C2/c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.048 and Rw of 0.066 for 2629 reflections with I ≥ 3σ(I). The central part of the molecule consists of two fused five-membered rings. One of them is a familiar BOCCN ring while the other is a novel and nearly planar BOBON ring containing one tetrahedral boron atom and one trigonal planar boron atom. Bond lengths are: O—B, 1.337(2)–1.467(2), N—B, 1.692(2), O—N, 1.440(2), O—C, 1.426(2), N—C, 1.513(2), B—C, 1.557(2) and 1.599(2), C(sp3)—C(sp3), 1.520(2)–1.530(2), C—C(ar), 1.372(4)–1.407(2), N—H, 0.89(2), mean C(ar)—H, 0.97(1), and mean C(sp3)—H, 1.01(1) Å. The crystal structure consists of discrete molecules each linked to two others by N—H … O hydrogen bonds (N … O = 2.853(2) Å).

Crystal and Molecular Structure of B-Phenyl-diptychboroxazolidine,

1975 ◽  
Vol 53 (10) ◽  
pp. 1393-1401 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Thermal Motion ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of B-phenyl-dictychboroxazolidine are monoclinic, a = 8.4977(4), b = 9.0617(5), c = 7.0105(3) Å, β = 111.627(3)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.040 for 967 reflections with I ≥ 3σ(I). The bond lengths involving nonhydrogen atoms have been corrected for thermal motion. Bond lengths are: B—O, 1.460(3) and 1.474(3), B—N, 1.666(3), B—C, 1.613(3), C—O, 1.411(3) and 1.419(3), C—N, 1.485(3) and 1.486(3), C(sp3)—C(sp3), 1.514(4) and 1.524(4), C—C(ar), 1.384–1.400(4–6), mean C—H, 0.98(4), and N—H, 0.87(5) Å. The crystal structure consists of discrete molecules of B-phenyl-diptychboroxazolidine each linked to two others by N—H … O hydrogen bonds (O … N = 2.914(3) Å) to form continuous spirals along b.

An X-Ray Study of the Synthetic Intermediate 9-Cyano-1,10-Dimethyl-6-Ethylenedioxy-1-Octalin

1975 ◽  
Vol 53 (2) ◽  
pp. 192-194 ◽  
Author(s):  
Harry Lynton ◽  
Pik-Yuen Siew
Keyword(s):  
Crystal Structure ◽  
Total Synthesis ◽  
Direct Methods ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Ring Junction ◽  
Cell Dimensions ◽  
R Value ◽  
Synthetic Intermediate

The crystal structure of the synthetic intermediate, 9-cyano-1,10-dimethyl-6-ethy]enedioxy-1-octalin, C15H21O2N, was solved by direct methods. The compound crystallizes in the space group p21/c with cell dimensions a = 12.282(4), b = 7.144(3), c = 15.619(5) Å, β = 104.04(1)°. Refinement was carried out isotropically for hydrogen and anisotropically for non-hydrogen atoms using full matrix least squares to an R-value of 0.043 for 1669 observed reflections.This compound, which has a cis configuration at the octalin ring junction, is a precursor to a moiety of the alkaloid thelepogine. The cis conformation is essential for total synthesis of thelopogine by this route.

Crystal and Molecular Structure of (±)-7,7-(2′,2′-Dimethyl)pentamethylene-1-methyl-norbornane-2-oxime

1975 ◽  
Vol 53 (5) ◽  
pp. 765-776 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Centrosymmetric Dimers

Crystals of (±)-7,7-(2′,2′-dimethyl)pentamethylene-1-methyl-norbornane-2-oxime are monoclinic, a = 9.202(2), b = 12.852(3), c = 12.698(3) Å, β = 110.83(2)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.048 for 1538 reflections with I ≥ 3σ(I). The crystal structure consists of pairs of molecules linked by N … H—O hydrogen bonds (N … O = 2.821(3) Å ) to form centrosymmetric dimers. Bond distances are as follows: C—N = 1.266(3), N—O = 1.426(3), mean C(sp3)—C(sp3) = 1.540, and mean C(sp3)—C(sp3) = 1.511 Å.

Crystal and molecular structure of unsubstituted and p-methoxy-substituted acetylbenzoylmethanatoboron difluoride

1997 ◽  
Vol 212 (5) ◽  
Author(s):  
Y. Dromzée ◽  
J. Kossanyi ◽  
V. Wintgens ◽  
P. Valat ◽  
H. Hartmann ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Crystal Structure Analysis ◽  
Full Matrix

AbstractThe crystal structures of two borines were solved by direct methods and refined by full-matrix least-squares procedure. 6-methyl-4-phenyl-1,3,2-(2The crystal structure analysis of compound

Crystal and Molecular Structure of 2-Deacylusnic Acid

1974 ◽  
Vol 52 (5) ◽  
pp. 723-733 ◽  
Author(s):  
Alistair L. Macdonald ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Structural Feature ◽  
Absolute Configuration ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Anomalous Scattering ◽  
Full Matrix

Crystals of the title compound are monoclinic a = 9.801(2) b = 9.120(1) c = 8.026(2) Å, β = 107.45(1)°, Z = 2, space group P21. The structure was determined by direct methods, and refined by electron-density and full-matrix least-squares procedures to R = 0.0325 for 1363 observed reflections. An attempt to determine the absolute configuration by use of the anomalous scattering of oxygen and carbon atoms has been made. The most important structural feature is delocalization in the cyclohexadiene ring. There are two intramolecular O—H … O hydrogen bonds, O … O distances 2.532(3) and 2.712(2) Å. The crystal structure consists of molecules linked by intermolecular O—H … O hydrogen bonds, O … O = 2.625(2)Å, to form continuous spirals about the 21 axes.

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