The chemistry of lauren-1-ene. V. The structure of an acid-catalysed rearrangement product

1983 ◽  
Vol 36 (12) ◽  
pp. 2581 ◽  
Author(s):  
LR Hanton ◽  
J Simpson ◽  
RT Weavers
Keyword(s):  
Formic Acid ◽  
Major Product ◽  
Rearrangement Product ◽  
X Ray

The major product from the formic-acid-induced rearrangement of lauren-1-ene has been confirmed to be (1S,4S,8R,9S,12R)-4,8,12,14,15-pentamethyltetracyclo[10,3,0,01,9,O4,9]pentadec-14-ene by X-ray analysis of a derived diol.

scholarly journals Hydrogen Production by Formic Acid Decomposition over Ca Promoted Ni/SiO2 Catalysts: Effect of the Calcium Content

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1516
Author(s):  
B. Faroldi ◽  
M. A. Paviotti ◽  
M. Camino-Manjarrés ◽  
S. González-Carrazán ◽  
C. López-Olmos ◽  
...  
Keyword(s):  
Formic Acid ◽  
Photoelectron Spectroscopy ◽  
Noble Metals ◽  
Heterogeneous Catalysts ◽  
Earth Metal ◽  
Major Product ◽  
Catalytic Dehydrogenation ◽  
Acid Decomposition ◽  
X Ray ◽  
Formic Acid Decomposition

Formic acid, a major product of biomass processing, is regarded as a potential liquid carrier for hydrogen storage and delivery. The catalytic dehydrogenation of FA to generate hydrogen using heterogeneous catalysts is of great interest. Ni based catalysts supported on silica were synthesized by incipient wet impregnation. The effect of doping with an alkaline earth metal (calcium) was studied, and the solids were tested in the formic acid decomposition reaction to produce hydrogen. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and programmed temperature surface reaction (TPSR). The catalyst doped with 19.3 wt.% of Ca showed 100% conversion of formic acid at 160 °C, with a 92% of selectivity to hydrogen. In addition, all the tested materials were promising for their application, since they showed catalytic behaviors (conversion and selectivity to hydrogen) comparable to those of noble metals reported in the literature.

scholarly journals Crystallization and preliminary X-ray characterization of the 2,4′-dihydroxyacetophenone dioxygenase fromAlcaligenessp. 4HAP

2014 ◽  
Vol 70 (6) ◽  
pp. 823-826 ◽  
Author(s):  
G. Beaven ◽  
A. Bowyer ◽  
P. Erskine ◽  
S. P. Wood ◽  
A. McCoy ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Formic Acid ◽  
Molecular Oxygen ◽  
Aromatic Ring ◽  
Bond Cleavage ◽  
Its Sequence ◽  
Hydroxybenzoic Acid ◽  
X Ray

The enzyme 2,4′-dihydroxyacetophenone dioxygenase (or DAD) catalyses the conversion of 2,4′-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid with the incorporation of molecular oxygen. Whilst the vast majority of dioxygenases cleave within the aromatic ring of the substrate, DAD is very unusual in that it is involved in C—C bond cleavage in a substituent of the aromatic ring. There is evidence that the enzyme is a homotetramer of 20.3 kDa subunits each containing nonhaem iron and its sequence suggests that it belongs to the cupin family of dioxygenases. By the use of limited chymotrypsinolysis, the DAD enzyme fromAlcaligenessp. 4HAP has been crystallized in a form that diffracts synchrotron radiation to a resolution of 2.2 Å.

scholarly journals Oxidation of Cyclohexane to Cylohexanol and Cyclohexanone Over H4[a-SiW12O40]/TiO2 Catalyst

2018 ◽  
Vol 16 (2) ◽  
pp. 175 ◽  
Author(s):  
Aldes Lesbani ◽  
Fatmawati Fatmawati ◽  
Risfidian Mohadi ◽  
Najma Annuria Fithri ◽  
Dedi Rohendi
Keyword(s):  
Hydrogen Peroxide ◽  
Ftir Spectroscopy ◽  
Mild Condition ◽  
Heterogeneous System ◽  
Pattern Analysis ◽  
Major Product ◽  
Ftir Spectrum ◽  
Powder Pattern ◽  
X Ray ◽  
Tio2 Catalyst

Oxidation of cyclohexane to cyclohexanol and cyclohexanone was carried out using H4[a-SiW12O40]/TiO2 as catalyst. In the first experiment, catalyst H4[a-SiW12O40]/TiO2 was synthesized and characterized using FTIR spectroscopy and X-Ray analysis. In the second experiment, catalyst H4[a-SiW12O40]/TiO2 was applied for conversion of cyclohexane. The conversion of cyclohexane was monitored using GC and GCMS. The results showed that H4[a-SiW12O40]/TiO2 was successfully synthesized using 1 g of H4[a-SiW12O40] and 0.5 g of TiO2. The FTIR spectrum showed vibration of H4[a-SiW12O40] appeared at 771-979 cm-1 and TiO2 at 520-680 cm-1. The XRD powder pattern analysis indicated that crystallinity of catalyst still remained after impregnation to form H4[a-SiW12O40]/TiO2. The H4[a-SiW12O40]/TiO2 catalyst was used for oxidation of cyclohexane in heterogeneous system under mild condition at 2 h, 70 °C, 0.038 g catalyst, and 3 mL hydrogen peroxide to give cyclohexanone as major product.

scholarly journals Crystal structure of 1,4-bis[5-(2-methoxyphenyl)-2H-tetrazol-2-yl]butane

2019 ◽  
Vol 75 (12) ◽  
pp. 1844-1847
Author(s):  
Young Min Byun ◽  
Farwa Ume ◽  
Ji Yeon Ryu ◽  
Junseong Lee ◽  
Hyoung-Ryun Park
Keyword(s):  
Title Compound ◽  
Methoxy Group ◽  
Coupling Reaction ◽  
Major Product ◽  
Molar Ratio ◽  
Dihedral Angles ◽  
X Ray ◽  
Compound C ◽  
Crystallographic Study ◽  
Centrosymmetric Dimers

The title compound, C20H22N8O2, was synthesized by the coupling reaction of a sodium tetrazolate salt and dibromobutane in a molar ratio of 2:1. The reaction can produce several possible regioisomers and the title compound was separated as the major product. The X-ray crystallographic study confirmed that the title compound crystallizes in the monoclinic P21/c space group and possesses a bridging butylene group that connects two identical phenyl tetrazole moieties. The butylene group is attached not to the first but the second nitrogen atoms of both tetrazole rings. The dihedral angles between the phenyl groups and the adjacent tetrazolyl rings are 5.32 (6) and 15.37 (7)°. In the crystal, the molecules form centrosymmetric dimers through C—H...O hydrogen bonds between a C—H group of the butylene linker and the O atom of a methoxy group.

A Facile Synthesis of a 2,2,3,3-Tetrasubstituted Tetrahydropyran

1991 ◽  
Vol 44 (8) ◽  
pp. 1115
Author(s):  
DJ Brecknell ◽  
RM Carman ◽  
WT Robinson ◽  
RC Schumann
Keyword(s):  
Major Product ◽  
Single Bond ◽  
Facile Synthesis ◽  
X Ray ◽  
X Ray Crystallography

An unusually facile acid- catalysed condensation has been observed between acetone and the unsaturated diol (3), producing a mixture of isomeric bicyclic tetrahydropyrans (6) and (8), with the formation of a new fully substituted carbon-carbon single bond. The structures were determined by n.m.r. and that of the major product (6) was confirmed by X-ray crystallography.

Preparation, and complexes with nickel(II) and copper(II), of a diazepane amine alcohol. The structure of [4,4-dimethyl-7-(5,5,7-trimethyl-1,4-diazepan-1-yl)-5-azaheptan-2-ol]nickel(II) perchlorate

1983 ◽  
Vol 36 (7) ◽  
pp. 1341 ◽  
Author(s):  
KR Morgan ◽  
GJ Gainsford ◽  
NF Curtis
Keyword(s):  
Ground State ◽  
Coordination Compounds ◽  
Major Product ◽  
Boat Conformation ◽  
Singlet Ground State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Donor ◽  
Square Planar ◽  
Coordination Plane

Reduction of 4,4,12,12-tetramethyl-5,8,11-triazapentadecane-2,14-dione diperchlorate by sodium borohydride yields as the major product one isomer of 4,4-dimethyl-7-(5,5,7-trimethyl-1,2-diazepam 1-yl)-5-azaheptan-2-ol, pyaz. The coordination compounds [M(pyaz)] (ClO4), and [Ni(pyaz)(NCS)] CNS (M = NiII, CuII) were prepared, the latter being assigned five-coordinate structures. The structure of singlet ground state [Ni(pyaz)] (ClO4)2 was determined by X-ray diffraction [space group P212121, Z 4, a 1450.8(2), b 1522.2(1), c 1048.5(1) pm, R 0.0675, Rw 0.0768 for 2461 reflections]. The compound has a square-planar coordination arrangement, with the three nitrogen and the oxygen donor atoms of the pyaz ligand approximately coplanar [Ni-O 190.0(6) pm; Ni-N 192.8(6), 189.2(6), 189.2(6) pm in sequence N(5) of chain, N(l), N(4) of diazepane]. The diazepane ring adopts a boat conformation. One side of the nickel(II) coordination plane is sterically crowded by the presence of two axial methyl substituents. The ligand has two non-equivalent chiral centres (C(14) of the diazepane ring and C(2) of the amine alcohol chain), both present in the R configuration in the crystal studied. The three nitrogen atoms, which became chiral centres upon coordination, are present in the S configuration for two diazepane nitrogen atoms and in the R configuration for the 5-aza chain nitrogen.

Photorearrangement of 2-cyanobicyclo[2.2.1]hept-2-ene. Observation of 1,2- and 1,3-sigmatropic shifts

1982 ◽  
Vol 60 (13) ◽  
pp. 1657-1663 ◽  
Author(s):  
Ikbal A. Akhtar ◽  
John J. McCullough ◽  
Susan Vaitekunas ◽  
Romolo Faggiani ◽  
Colin J. L. Lock
Keyword(s):  
Single Crystals ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Major Product ◽  
Molecular Structures ◽  
Lithium Aluminum ◽  
Mercury Vapour ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Mercury Vapour Lamp

Irradiation of 2-cyanobicyclo[2.2.1]hept-2-ene (2-cyanonorbornene, 4) in hexane, with the full arc of a mercury vapour lamp, gives the rearrangement products 1-cyanobicyclo[4.1.0]hept-2-ene 5 and 7-cyanotricyclo[4.1.0.03.7]heptane 6 in the ratio 20:1. These products were separated by preparative vpc. The structure of the major product 5 was determined by single crystal X-ray analysis. Reduction of 5 with lithium aluminum hydride gave the corresponding primary amine, which was converted to the p-bromobenzenesulfonamide 9, mp 150–151 °C, which gave single crystals from ethanol–water. The crystal and molecular structures are described. The minor product 6 was hydrogenated to give 7-cyanobicyclo[2.2. 1]heptane. Formation of 5 and 6 may involve concerted σ2s + π2s and σ2a + π2a processes respectively, which are photochemically allowed.

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