Structure of Ethylene Propylene Dicyclopentadiene Terpolymers

1966 ◽  
Vol 39 (4) ◽  
pp. 964-968
Author(s):  
W. Cooper ◽  
D. E. Eaves ◽  
M. E. Tunnicloffe ◽  
G. Vaughan
Keyword(s):  
Double Bond ◽  
Infrared Spectra ◽  
Ring Opening ◽  
Iodine Monochloride ◽  
Model Compounds ◽  
Ethylene Propylene

Abstract Terpolymers of ethylene, propylenc and C14-dicyclopentadiene have been compared with model compounds to determine the structure of combined termonomer units. Reactions with iodine monochloride, bromine and the infrared spectra of the terpolymers indicate that dicyclopentadiene polymerizes at the 9,10 double bond without ring-opening or disproportionation.

Structure and Content of Dicyclopentadiene in Ethylene Propylene Dicyclopentadiene Terpolymers

1967 ◽  
Vol 40 (2) ◽  
pp. 563-568
Author(s):  
R. J. de Kock ◽  
A. Veermans
Keyword(s):  
Double Bond ◽  
Polymer Chain ◽  
Spectroscopic Methods ◽  
Double Bonds ◽  
Model Compounds ◽  
Ethylene Propylene ◽  
Infrared Spectroscopic ◽  
Polymerization Mixture ◽  
Derivatives Of

Abstract With the aid of model compounds—derivatives of endo- and exo-dicyclopentadiene—it has been established that a) the 9, 10-double bond (the double bond in the norbornane ring) is involved in the polymerization of dicyclopentadiene with ethylene and propylene, b) dicyclopentadiene, present in the polymerization mixture in the endo-configuration, occurs in the exo-configuration in the polymer chain. The same model compounds enable the dicyclopentadiene content of ethylene propylene dicyclopentadiene terpolymers to be determined by infrared spectroscopic methods. Use is made of the 3045 cm−1 band, which is characteristic of endo-cyclic double bonds in five-membered rings.

Model Compounds Related to Saquayamycin. Attempts to Oxygenate the A/B Ring Junction

2002 ◽  
Vol 55 (5) ◽  
pp. 343 ◽  
Author(s):  
M. A. Apponyi ◽  
J. H. Bowie ◽  
B. W. Skelton ◽  
A. H. White
Keyword(s):  
Double Bond ◽  
Maleic Anhydride ◽  
Good Yield ◽  
Ring Opening ◽  
Diels Alder ◽  
Aromatic System ◽  
Model Compounds ◽  
Similar Treatment ◽  
Ring Junction

The aim of this project was to attempt to find a method for introducing the cis-dihydroxyl substitution at the A/B-ring junction of model compounds related to the saquayamycins. The Diels-Alder reactions of maleic anhydride and bromomaleic anhydride with 5,5-dimethyl-3-vinylcyclohexa-1,2-dienyl acetate gave the two required endo-adducts in good yield, namely (octahydrobenzo[e]isobenzofuran-9-yl acetate (6) and (octahydrobenzo[e]isobenzofuran-9-yl acetate (9). Each of these was converted into the B-ring mono-epoxide, namely (H-benzo[e]oxireno-2,3-furan-1-yl acetate (7) and a mixture of two racemic diastereoisomers of 9a-bromo-3,3-dimethyl-7,9-dioxoperhydrobenzo[e]oxi- reno[2,3-f]isobenzofuran-1-yl acetate (12), respectively. It was then hoped to deprotonate both (7) and (12) at the 9a position in order to effect migration of the 8,9 double bond to the 9,9a position. Reaction of (7) with a mild base (pyridine) did not effect any reaction. Similar treatment of (12) did remove the 9a proton, but it also effected ring opening of the epoxide, followed by dehydration and dehydrobromination to give an excellent (but unwanted) yield of the aromatized system (±)-7,7-dimethyl-1,3-dioxo-1,3,5,7-tetrahydrobenzo (e]isobenzofuran-9-yl acetate. Dehydrobromination of (9), and deprotonation of the 9a position, similarly formed the aromatic system (e]isobenzofuran-9-yl acetate (11) in good yield.

Configuration on the C=N double bond of monosubstituted amidines and amidoximes

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Steric Effects ◽  
Model Compounds ◽  
X Ray ◽  
Analogous Model

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

scholarly journals Phenolation of vegetable oils

2011 ◽  
Vol 76 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Mihail Ionescu ◽  
Zoran Petrovic
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Double Bond ◽  
Vegetable Oils ◽  
Raw Materials ◽  
Complex Mixture ◽  
Double Bonds ◽  
Triflic Acid ◽  
Model Compounds ◽  
Phenol Alkylation

Novel bio-based compounds containing phenols suitable for the synthesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid) as catalysts was studied. The reaction kinetics was followed by monitoring the decrease of the double bond content (iodine value) with time. In order to understand the mechanism of the reaction, phenol was alkylated with model compounds. The model compounds containing one internal double bond were 9-octadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82% oleic acid). It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid). Fatty acids with two double bonds (linoleic acid) and three double bonds (linolenic acid) lead to polymerized oils by a Diels Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with polymerized oil (30-60%), phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 %) and unreacted oil (30%). The phenolated vegetable oils are new aromatic-aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions) for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.

1H-1,3-Diazepines and Ketenimines from Cyanotetrazolopyridines

2008 ◽  
Vol 61 (8) ◽  
pp. 592 ◽  
Author(s):  
Chris Addicott ◽  
Curt Wentrup
Keyword(s):  
Infrared Spectra ◽  
Ring Opening ◽  
Ring Expansion ◽  
Secondary Amines ◽  
Argon Matrix ◽  
The Matrix ◽  
Nitrogen Elimination ◽  
Isolated Species

Cyano-substituted tetrazolo[1,5-a]pyridines/2-azidopyridines 8T and 15T undergo thermal ring opening to the azides 8A and 15A. Solution photolysis causes nitrogen elimination and ring expansion to 1,3-diazacyclohepta-1,2,4,6-tetraenes 10 and 17, which react with alcohols to afford 2-alkoxy-1H-1,3-diazepines, with secondary amines to 2-dialkylamino-5H-1,3-diazepines, and with water to 1,3-diazepin-2-ones (12–14, 19, 21). Argon matrix photolysis of the azides affords the diazacycloheptatetraenes 10 and 17 as principal products together with ring-opened dicyanovinylketenimines 11 and 18. The matrix-isolated species were identified on the basis of comparison of the infrared spectra with those calculated at the B3LYP/6–31+G* level.

A P–H functionalized Al/P-based frustrated Lewis pair – hydrophosphination of nitriles, ring opening with cyclopropenones and evidence of PC double bond formation

2018 ◽  
Vol 47 (25) ◽  
pp. 8402-8417 ◽  
Author(s):  
Lukas Keweloh ◽  
Niklas Aders ◽  
Alexander Hepp ◽  
Damian Pleschka ◽  
Ernst-Ulrich Würthwein ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Bond Formation ◽  
Frustrated Lewis Pair

A P–H functionalized FLP reacted with RX-CN by hydrophosphination. Ring opening by treatment with cyclopropenthione resulted in PC bond formation.

FURTHER EVIDENCE FOR CYCLIC MONOMERS IN HEATED LINSEED OIL

1961 ◽  
Vol 39 (10) ◽  
pp. 1906-1914 ◽  
Author(s):  
A. G. McInnes ◽  
F. P. Cooper ◽  
J. A. MacDonald
Keyword(s):  
Double Bond ◽  
Infrared Spectra ◽  
Chemical Structure ◽  
Linseed Oil ◽  
Carbon Skeleton ◽  
Side Chain ◽  
Partition Chromatography

The distillable esters of heated linseed oil contain a fraction, designated NAFD, which fails to form an adduct with urea. NAFD itself has now been separated into three fractions by gas-liquid partition chromatography. The chemical structure of these component esters was investigated by means of their infrared spectra and by analysis of the products obtained on oxidation of the esters with periodate–permanganate. It is concluded that all the components have the same carbon skeleton, namely, 1-propyl-2-alkenecarboxycyclohexene, but differ in the position of the double bond in the side chain.

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