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Showing papers on "Ether published in 1977"


Journal ArticleDOI
TL;DR: The glycerol ethers are proposed to be unique fully saturated diglycerol tetraethers, primarily C86H172O6, Mr 1300, which contain two sn-2,3-glycerol residues bridged through ether linkages by two C40 isopranoid branched diols.

211 citations


Journal ArticleDOI
01 Nov 1977-Lipids
TL;DR: In this paper, a structural investigation of methyl oleate was carried out by gas chromatography-mass spectrometry (GC-MS) of trimethylsilyl (TMS) ether derivatives.
Abstract: A structural investigation of autoxidation products of methyl oleate was carried out by gas chromatography-mass spectrometry (GC-MS) of trimethylsilyl (TMS) ether derivatives. GC-MS using computer plots of selected masses afforded structural assignments of GC peaks due to incompletely resolved mixtures. This method provided evidence of epoxy and keto esters which are not completely separated from the main components consisting of the TMS derivatives of the allylic hydroxy esters. Use of an MS-computer system also showed that the hydroxyoctadecanoate TMS ethers were partially separated by GC. The use of synthetic hydroxyoctadecanoates for the first time enabled us to demonstrate the quantitative reliability of a GC-MS computer summation approach to analyze the isomeric composition of oleate hydroperoxides (as the saturated TMS ether derivatives). Consistently higher concentrations were found of the 8- and 11-hydroperoxides than of the 9- and 10-hydroperoxides. Minor products of autoxidation identified by GC-MS include allylic enones, isomeric epoxyoctadecanoates, dihydroxyctadecenoates, and dihydroxyoctadecanoates.

162 citations


Journal ArticleDOI
TL;DR: In this article, the use of α-metalated isocyanides as synthons for α metalated primary amines has been discussed, where they can be used for synthesis of higher amino acids starting from simple amino acids.
Abstract: Being both nucleophilic and electrophilic, α-metalated isocyanides can add to polar double bonds, forming heterocycles. They are also synthons for α-metalated primary amines. This article describes recent or improved procedures for their use in organic synthesis: (1) In heterocyclic syntheses to give 2-oxazolines, 2-imidazolines, 2-thiazolines, oxazoles and oligooxazoles, thiazoles, triazoles, imidazolinones, pyrroles, 5,6-dihydro-1,3-oxazines and -thiazines, and (via cycloaddition with nitrones) 2-imidazolidinones. (2) In the field of formylaminomethylenation, for example transformation of estrone methyl ether and a keto sugar into the corresponding α-formylaminoacrylic esters, and the conversion of aldehydes and ketones by 3- and 4-pyridyl-methyl isocyanides into N-(1-pyridyl-1-alkenyl)formamides and their hydrolysis to 3- and 4-acylpyridines. (3) In connection with the use of α-metalated isocyanides as synthons for α-metalated primary amines, the author demonstrates how they may be used for preparation of 1,2- and 1,3-amino alcohols, 1,2-diamines, 2,3-diaminoalkanoic acids and for synthesis of higher amino acids starting from simple amino acids.

158 citations


Journal ArticleDOI
TL;DR: In this paper, an experimental study was carried out on addition of alcohols to tertiary olefins catalyzed by a macroporous sulfonic acid resin, and the ion exchange resin displays an activity higher than soluble anhydrous p -toluenesulfonic acid.

152 citations


Journal ArticleDOI
TL;DR: In this paper, the reaction of noncyclic poly(oxyethylene) derivatives with alkali and alkaline earth metal ions was investigated by means of the solvent extraction of their thiocyanates or iodides.
Abstract: The reaction of noncyclic poly(oxyethylene) derivatives with alkali and alkaline earth metal ions was investigated by means of the solvent extraction of their thiocyanates or iodides. Polyethylene glycols with more than 23 oxyethylene units showed a strong extracting power comparable to those of the crown ethers, and the power increased with the increasing number of oxyethylene units in them. Extraction studies using homogeneous poly(oxyethylene) monododecyl ethers revealed that more than 7 oxyethylene units were necessary to bind the potassium ion in the water phase and to transfer the complexed salt to the organic phase, and that the extracting ability of octa(oxyethylene) monododecyl ether was about one sixth of that of 18-crown-6. The monododecyl ether is fairly effective as a complexing agent for potassium picrate even below its critical micelle concentration; the stoichiometry of the extractable complex was found to be 0.8:1 with respect to the ether and the picrate. There was no remarkable differen...

152 citations


Journal ArticleDOI
TL;DR: Nickel complexes (NiCl2 (2,2′-bipyridine) and NiBr2(triphenylphosphine)2) catalyze polycondensation of di- and polyhalogenated aromatic compounds including p-dibromobenzene, p-Dichlorobenzenes, m-dichloroberenzene and bis (4bromophenyl)ether, pchlorobenzyl chloride and 1,3,5-trichlorobinenzene by dehalogenation with magnesium to give polyphenylene
Abstract: Nickel complexes (NiCl2 (2,2′-bipyridine) and NiBr2(triphenylphosphine)2) catalyze polycondensation of di- and polyhalogenated aromatic compounds including p-dibromobenzene, p-dichlorobenzene, m-dichlorobenzene, bis (4-bromophenyl)ether, p-chlorobenzyl chloride and 1,3,5-trichlorobenzene by dehalogenation with magnesium to give polyphenylene type polymers in high yields.

131 citations


Journal ArticleDOI
TL;DR: In this paper, a value of the enthalpy of formation of the phenoxy radical in the gas phase, ΔH°,298K (ϕO·, g) = 11.4 ± 2.0 kcal/mol, has been obtained from the kinetic study of the unimolecular decompositions of phenyl ethyl ether, phenyl allyl ether and benzyl methyl ether at very low pressures.
Abstract: A value of the enthalpy of formation of the phenoxy radical in the gas phase, ΔH°,298K (ϕO·, g) = 11.4 ± 2.0 kcal/mol, has been obtained from the kinetic study of the unimolecular decompositions of phenyl ethyl ether, phenyl allyl ether, and benzyl methyl ether at very low pressures. Bond fission, producing phenoxy or benzyl radicals, respectively, is the only mode of decomposition in each case. The present value leads to a bond dissociation energy BDE(ϕO—H) = 86.5 ± 2 kcal/mol, in good agreement with recent estimates made on the basis of competitive oxidation steps in the liquid phase. A comparison with bond dissociation energies of aliphatic alcohols, BDE(RO—H) = 104 kcal/mol, reveals that the stabilization energy of the phenoxy radical (17.5 kcal/mol) is considerably greater than the one observed for the isoelectronic benzyl radical (13.2 kcal/mol). Decomposition of phenoxy radicals into cyclopentadienyl radicals and CO has been observed at temperatures above 1000°K, and a mechanism for this reaction is proposed.

126 citations


Journal ArticleDOI
TL;DR: The partial molar volumes of a number of ethers, ketones, esters and alcohols in water at 25.0°C have been determined and related to their van der Waals volumes by one of two equations, depending on whether the molecules are spherical or cylindrical in shape.
Abstract: The partial molar volumes of a number of ethers, ketones, esters and alcohols in water at 25.0°C have been determined and related to their van der Waals volumes by one of two equations, depending on whether the molecules are spherical or cylindrical in shape. Allowance has been made for the void volume associated with each molecule and the results imply that calculated volumes must be reduced by a constant amount for each carbonyl or hydroxyl group present, owing to hydrogen bonding to water. No such reduction in the calculated volume is required for the oxygen atom of an ether. It is shown for diols that the amount of void volume per additional —CH2— group remains constant for straight-chain compounds (i.e., cylinders), whereas for spherical molecules the amount of void volume decreases with increase in the number of carbon atoms, as predicted.

106 citations




Journal ArticleDOI
TL;DR: To determine total fecal bile acids, these are extracted with diethyl ether after boiling with a solution of potassium hydroxide in ethanediol and directly determined with 3 alpha-hydroxysteroid dehydrogenase.

Journal ArticleDOI
TL;DR: In this paper, the absolute rate constants for the reaction of OH radicals with dimethyl ether and vinyl methyl ether have been determined over the temperature range 299-427°K using a flash photolysis-resonance fluorescence technique.
Abstract: Absolute rate constants for the reaction of OH radicals with dimethyl ether and vinyl methyl ether have been determined over the temperature range 299–427 °K using a flash photolysis–resonance fluorescence technique. The Arrhenius expressions obtained were k (CH3OCH3) =1.29×10−11 e−(770±300)/RT cm3 molecule−1⋅sec−1, and k (CH2=CHOCH3) =6.10 ×10−12 e(1015±300)/RT cm3 molecule−1⋅sec−1, with rate constants at room temperature of k (CH3OCH3) = (3.50±0.35) ×10−12 cm3 molecule−1⋅sec−1 and k (CH2=CHOCH3) = (3.35±0.34) ×10−11 cm3 molecule−1⋅sec−1.

Patent
Jr. Gim F. Lee1
30 Sep 1977
TL;DR: In this article, a low molecular weight polyphenylene ether resin having an intrinsic viscosity of less than about 0.33 dl/g, as measured in chloroform at 30° C, was described.
Abstract: Novel compositions are disclosed which comprise a low molecular weight polyphenylene ether resin having an intrinsic viscosity of less than about 0.4 dl/g, preferably less than 0.33 dl/g, as measured in chloroform at 30° C., an elastomeric block copolymer of a vinyl aromatic compound and a conjugated diene, and a plasticizer. Also included within the scope of the invention are reinforced and flame-retardant compositions.


Patent
26 May 1977
TL;DR: A process for separating an aromatic hydrocarbon of the general formula "STR1" from a mixture comprising a compound and one or more aliphatic hydrocarbons, cyclo-aliphatic hydrates, alcohol, ether, ketone, or carboxylic acid esters is described in this article.
Abstract: A process for separating an aromatic hydrocarbon of the general formula ##STR1## wherein R represents an alkyl group having 1 to 3 carbon atoms and n is 0, 1, 2, or 3 (and wherein the groups R, when n is 2 or 3 can be the same or different), From a mixture comprising said compound and one or more aliphatic hydrocarbon, cycloaliphatic hydrocarbon, alcohol, ether, ketone or a carboxylic acid ester which comprises contacting said mixture with a polyurethane membrane.

Journal ArticleDOI
01 Apr 1977-Polymer
TL;DR: In this paper, the effects of structural factors on the ease with which polymers of high molecular weight could be obtained were examined and found to correlate with previous data concerning functional group reactivities.

Journal ArticleDOI
TL;DR: These DMAS ethers provide valuable information for structural elucidation of hydroxylated steroids by gas chromatography electron impact mass spectrometry.
Abstract: Differences in methylene unit values were used for the determination of the hydroxyl group number of a steroid by means of gas chromatography This index is defined as the difference in the methylene unit value between trimethylsilyl and other dimethylalkylsilyl (DMAS) ether derivatives of hydroxylated steroids, namely dimethylethylsilyl (DMES) and dimethyl-n-propylsilyl (DMPS) ethers The reactivities of DMES and DMPS imidazoles as silylating agents were nearly equal to that of TMS-I Mass spectra of these derivatives were characterized by the molecular ion cluster, [M]+, [M–15]+ and [M–29]+ (or [M–43]+) The molecular ion cluster of these derivatives is most useful for estimating the molecular weight Therefore, these DMAS ethers provide valuable information for structural elucidation of hydroxylated steroids by gas chromatography electron impact mass spectrometry

Journal ArticleDOI
TL;DR: Fully assigned 13 C-NMR spectra confirm the C 40 (16,16 -biphytanyl) structures of the alkyl chains in the ether lipids of extreme thermoacidophile bacteria of the Caldariella group.

Journal ArticleDOI
01 Apr 1977-Polymer
TL;DR: In this paper, the 4-halogenophenylsulphonyl phenols were used as intermediates for the synthesis of poly(arylene ether sulphones) by chlorosulphonylation of diphenyl carbonate.

Journal ArticleDOI
TL;DR: In this paper, the alkaline condensation of p-hydroxyaryl glycerol-β-aryl ether units in lignin with other phenolic structures and the subsequent reactions of the condensation products have been elucidated using a...
Abstract: The alkaline condensation of p-hydroxyarylglycerol-β-aryl ether units in lignin with other phenolic structures and the subsequent reactions of the condensation products have been elucidated using a...

Journal ArticleDOI
TL;DR: A series of macrocyclic ether-esters have been prepared by treating various glycols with adipoyl chloride and various substituted malonyl, succinyl and glutaryl chlorides as discussed by the authors.


Patent
05 Jul 1977
TL;DR: A flame-retardant polyphenylene ether resin composition comprising (I) 85 to 97% by weight of a resin consisting of (1) 20 to 90% of a poly phenylene ether of the formula (A): ##STR1## where R1 and R2 are each alkyl of 1 to 4 carbon atoms and m is the degree of polymerization, and (2) 80 to 10% or 3 to 15% of at least one member of the group consisting of phosphorus-containing compounds of formula (B):##STR2## where X is a
Abstract: A flame-retardant polyphenylene ether resin composition comprising (I) 85 to 97% by weight of a resin consisting of (1) 20 to 90% by weight of a polyphenylene ether of the formula (A): ##STR1## where R1 and R2 are each alkyl of 1 to 4 carbon atoms and m is the degree of polymerization, and (2) 80 to 10% by weight of a styrene type polymer and (II) 3 to 15% by weight of at least one member of the group consisting of phosphorus-containing compounds of formula (B): ##STR2## where X is a hydrogen atom, a hydroxyl group, an amino group, a halogen atom, an alkyl group of 1 to 10 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, an alkylthio of 1 to 10 carbon atoms, an aryloxy of 6 of 10 carbon atoms or hydroxy substituted aryloxy of 6 to 10 carbon atoms, Y1 and Y2 are each an alkyl of 1 to 8 carbon atoms, an alkoxy of 1 to 8 carbon atoms or an aryl group, Z is an oxygen or sulfur atom, n and p are each an integer of 0 to 4 and q is an integer of 0 or 1. Similar compositions are also prepared including styrene type compounded grafted to the polyphenylene ether and including organic phosphates and organic phosphites and/or melamine, benzoguanamine or their methylol or etherified methylol derivatives.

Journal ArticleDOI
TL;DR: The reaction of thiols with N2O4 in an inert organic solvent such as CCl4 or ether at low temperatures afforded aryl and alkyl thionitrites in quantitative yields.
Abstract: The reaction of thiols with N2O4 in an inert organic solvent such as CCl4 or ether at low temperatures afforded aryl and alkyl thionitrites in quantitative yields; the thionitrites thus obtained reacted very readily with other thiols or sulphinic acids to give unsymmetrical disulphides or thiolsulphonates in nearly quantitative yields.

Journal ArticleDOI
TL;DR: In this article, the anodic oxidation of 2,6-di-tert-butyl-4-isopropylphenol, Ia, as well as the 4-ethyl (Ib) and 4-methyl (Ic) derivatives, has been studied in acetonitrile using carbon electrodes.

Journal ArticleDOI
TL;DR: In this article, the catalytic decomposition of methanol on both anatase and rutile forms of TiO2 with a similar texture has been studied in connection with ir and TPD studies of the adsorbed phase.

Patent
15 Jul 1977
TL;DR: The reaction product of a hydroxy ether and a pentavalent phosphorus compound with a short chain and/or long chain alcohol can be employed to gel organic liquids by mixing the reaction product with an organic liquid in the presence of a multivalent metal cation as discussed by the authors.
Abstract: The reaction product of a hydroxy ether and a pentavalent phosphorus compound with a short chain and/or long chain alcohol can be employed to gel organic liquids by mixing the reaction product with an organic liquid in the presence of a multivalent metal cation.

Patent
29 Dec 1977
TL;DR: In this paper, a novel process for the polymerization of aziridine compounds is disclosed, which is based on mixing an Aziridine compound with a polymerization initiator having the formula: ##STR1## where R1 is an alkyl radical of 1 to 18 C atoms, R2 is an aryl radical which can be substituted with a chloro, nitro or alkoxy group, and A is an electron attracting radical.
Abstract: A novel process for the polymerization of aziridine compounds is disclosed. The polymerization process includes mixing an aziridine compound with a polymerization initiator having the formula: ##STR1## where R1 is an alkyl radical of 1 to 18 C atoms, R2 is an alkyl radical of 1 to 18 C atoms or a phenyl alkyl radical of 7 to 18 C atoms, wherein said alkyl radicals may contain an ester group and/or ether group, R3 and R4 are hydrogen, an alkyl radical of 1 to 18 C atoms, and/or an aryl radical which can be substituted with a chloro, nitro or alkoxy group, whereby the alkyl radicals of R3 and R4 together or in combination with B can form a cycloaliphatic or heterocyclic ring, B is an electron attracting radical, and A.sup.⊖ is a non-nucleophilic anion. Polyimines are quickly formed at ambient temperature.

Journal ArticleDOI
01 Apr 1977-Polymer
TL;DR: In this paper, the melting points and glass transition temperatures have been measured for a series of arylene ether sulphone homo-and co-polymers and it has been shown that structural changes in repeat unit structure cause marked changes in mechanical properties by altering the packing density of polymer repeat units rather than by changing chain polarity or rigidity.

Patent
07 Jun 1977
TL;DR: In this article, cellulose-based soil release ethers are used in detergent compositions containing C10 -C12 alkyl benzene sulfonate surfactants to provide optimal soil release performance.
Abstract: Cellulose-based soil release ethers are used in detergent compositions containing C10 -C12 alkyl benzene sulfonate surfactants, and substantially free from interfering longer-chain length alkyl benzene sulfonates, to provide optimal soil release performance.