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Showing papers on "Double bond published in 1969"


Journal ArticleDOI
TL;DR: The relations between the chemical structure of non-electrolytes and their ability to permeate cell membranes are analysed at the level of molecular forces, using the measurements of reflexion coefficients in gall-bladder epithelial cells tabulated in the preceding paper.
Abstract: The relations between the chemical structure of non-electrolytes and their ability to permeate cell membranes are analysed at the level of molecular forces, using the measurements of reflexion coefficients in gall-bladder epithelial cells tabulated in the preceding paper. Stronger solute: water forces and weaker solute: membrane forces are associated with lower permeating power. The portions of the membrane controlling non-electrolyte permeation behave as nearly pure hydrocarbons with very few hydrogen-bonding sites. Most substituents (hydroxyl, ether, carbonyl, ester, amino, amide, urea, nitrile) are shown to decrease permeation in proportion to the number and strength of intermolecular hydrogen bonds which they form with water, while intramolecular hydrogen bonding accelerates permeation. Carbon-carbon double bonds and triple bonds and aromatic residues decrease permeability due to hydrogen bonds involving $\pi $ electrons. Inductive effects, in which a substituent indirectly modifies permeability by withdrawing or releasing electrons at an adjacent hydrogen bonding site, are most noticeable for halogens, the nitro group, double and triple bonds, and branched alkyl groups. Altered forces between membrane hydrocarbons and the solute retard the permeation (weaker forces) of fluorine compounds and branched compounds, and slightly accelerate the permeation (stronger forces) of other halogen derivatives and compounds with long carbon chains. The main factor in the increase of permeability with increasing hydrocarbon chain length is an entropy effect associated with a change in local water structure; and this effect is partly responsible for the decrease in permeability with chain branching, whose origin is particularly complex.

128 citations


Journal ArticleDOI
TL;DR: Purified soybean lipoxidase was used to test the substrate specificity of all cis,cis-methylene-interrupted isomers of linoleic acid and the natural 9,12-isomer was found to be the best substrate, and the 13,16-isomers 50% as effective, the presence of calcium ions broadened the pattern of specificity.

101 citations



Journal ArticleDOI
TL;DR: In this paper, the carbon ring is planar with valence angles 94.2° (at the double bond) and 85.8°, and the C(1)-C(2) distance is 1.342 A.

64 citations


Journal ArticleDOI
TL;DR: In this article, the isolation of a pure sesquiterpene hydrocarbon from the natural coating of Granny Smith apples was described, based on its ultraviolet, infrared, mass, and N.M.R. spectra, which established it as an α-farnesene stereoisomer with a trans configuration assigned to the 9,10 double bond and a likely trans configuration of the 6,7 bond.
Abstract: The isolation of a pure sesquiterpene hydrocarbon from the natural coating of Granny Smith apples is described. Evidence mainly from its ultraviolet, infrared, mass, and N.M.R. spectra establish it as an α- farnesene stereoisomer (I) with a trans configuration assigned to the 9,10 double bond and a likely trans configuration of the 6,7 bond. Its infrared, mass, and N.M.R. spectra and those of trans-β-farnesene (II) are reported.

63 citations


Journal ArticleDOI
TL;DR: The photochemistry of conjugated cyclohexenones O-acetyl testosterone (1) and 10-methyl-Δ1,9-octalone-(2) has been investigated in detail as discussed by the authors.
Abstract: The photochemistry of the conjugated cyclohexenones O-acetyl testosterone (1) and 10-methyl-Δ1,9-octalone-(2) (24) has been investigated in detail. The choice of reaction paths of both ketones depends strongly on the solvent used. In t-butanol, a photostationary equilibrium 1 ⇄ 3 is reached which is depleted solely by the parallel rearrangement 1 5 (Chart 1; for earlier results on these reactions see [2a] [6] [7]). In benzene, double bond shift 1 16 (Chart 3) occurs instead, which is due to hydrogen abstraction from a ground-state ketone by the oxygen of an excited ketone as the primary photochemical process. In toluene, the major reaction is solvent incorporation (1 17, Chart 4) through hydrogen addition to the β-carbon of the enone, accompanied by double bond shift and formation of saturated dihydroketone as the minor reactions. Contrary in part to an earlier report [19], the photochemical transformation of the bicyclic enone 24 exhibit a similar solvent dependence. The corresponding products 25–29 are summarized in Chart 5 and Table 1. Sensitization and quenching experiments established the triplet nature of the above reactions of 1 and 24. Based on STERN-VOLMER analyses of the quenching data (cf. Figures 2, 4–8, and Table 3), rearrangement, double bond reduction and toluene addition are attributed to one triplet state of the enones which is assigned tentatively as 3(π, π*) state, and the double bond shift is attributed to another triplet assigned as 3(n, π*) state (cf. Figure 9). The stereospecific rearrangement of the 1α-deuterated ketone 2 to the 4β-deuterio isomer 4 shows the reaction to proceed with retention at C-1 and inversion at C-10. The 4-substituted testosterone derivatives 33–36 (Chart 8) were found to be much less reactive in general than 1. In particular, 4-methyl ketone 33 remains essentially unchanged on irradiation in t-butanol, benzene and toluene.

60 citations


Journal ArticleDOI
TL;DR: The thermal isomerization rates of several conjugated ketene-mercaptoaminals involving rotation about a CC double bond were found to be within the NMR time scale as mentioned in this paper.

54 citations


Journal ArticleDOI
01 Jan 1969-Lipids
TL;DR: Saturated, monoenoic and dienoic wax esters, C26−C40, have been synthesized from even-numbered fatty alcohols and acids, and those esters which have an acid moiety two carbon atoms shorter than the alcohol moiety have melting points higher than interpolation would predict.
Abstract: Saturated, monoenoic and dienoic wax esters, C26−C40, have been synthesized from even-numbered fatty alcohols and acids. In homologous series of saturated esters, the increments of melting points follow a regular trend except for those esters which have an acid moiety two carbon atoms shorter than the alcohol moiety. These wax esters have melting points higher than interpolation would predict. Monoenoic wax esters with the double bond in the alcohol chain have melting points about 10 C higher than their isomers with the double bond in the acid chain.

54 citations



Journal ArticleDOI
01 Mar 1969-Lipids
TL;DR: In this article, the Stein-Nicolaides procedure was used for the identification of unknown olefinic fatty acids by ozonolysis of monoenoic esters.
Abstract: Increased versatility has been achieved in the identification of unknown olefinic fatty acids by ozonolysis. The method has been applied to purified methyl esters containing up to four double bonds. Aldehydic fragments, obtained from esters by the Stein-Nicolaides procedure (2), were determined by GLC on two columns of different polarity. Equivalent chain lengths of each fragment on the two columns provide identification. For monoenoic esters the location of the double bond is clearly indicated by the aldehyde and aldehyde-ester fragments. Dienes are identified by the aldehyde and aldehyde-ester fragments when the original chain length of the ester is known; the dialdehyde fragment provides confirmatory evidence. Trienes and tetraenes are analyzed by interrupting the ozonolysis at various times, thereby producing unsaturated, as well as saturated, aldehydes and aldehyde-esters. Unsaturated fragments locate the central or interior double bonds.

51 citations


Journal ArticleDOI
01 Jul 1969-Lipids
TL;DR: Trans isomerization of monoenoic and dienoic fatty acid methyl esters has been carried out with thiols and diphenylphosphine in the presence of azobisisobutylnitrile and there was no migration of the double bonds.
Abstract: Trans isomerization of monoenoic and dienoic fatty acid methyl esters has been carried out with thiols and diphenylphosphine in the presence of azobisisobutylnitrile. The equilibrium mixture contained 75–80%trans double bonds and there was no migration of the double bonds.

Journal ArticleDOI
TL;DR: It was concluded that the C-26 oxygenation of cholesterol during its biosynthetic conversion to tigogenin in D. samen, does not require the intermediacy of a C-24 (or C-25) double bond.


Journal ArticleDOI
TL;DR: In this article, the Raman spectra of polyisoprene was analyzed and the frequencies of the carbon-carbon double bond vibrations were used to describe the structure content of the structure.
Abstract: The Raman spectra of cis-1,4-, trans-1,4-, and 3,4-polyisoprene are presented, and the frequencies are classified by configurational structure type. The stretching frequency of the carbon-carbon double bond vibrations are used to describe structure content. Only Raman bands characteristic of total 1,4 content and total vinyl content can be observed. Tentative values of structure content determined by both peak height and peak area are presented for two mixed structure rubbers.

Journal ArticleDOI
TL;DR: In this article, Cinnamaldehyde is reduced at the dropping mercury electrode in two main two-electron steps, in the first the CC double bond is reduced and in the second the aldehydic group.
Abstract: Cinnamaldehyde is reduced at the dropping mercury electrode in two main two-electron steps. In the first the CC double bond is reduced, in the second the aldehydic group. The rate of dehydration of 3-phenylpropionaldehyde governs the height of the more negative step. In acid media the first two-electron process is split into two one-electron steps. The radical formed in the first one-electron step can react with cations and the adduct formed gives a separate wave iN. In electrolyses with electrodes which do not have a periodically renewed surface (mercury pool and hanging mercury drop electrodes, single-sweep techniques) the radical formed undergoes further reactions and can eventually polymerize.


Journal ArticleDOI
TL;DR: On treatment with boron trifluoride-diethyl ether in benzene solution, tri-O-acetyl-D-glucal dimerises as discussed by the authors.
Abstract: On treatment with boron trifluoride–diethyl ether in benzene solution, tri-O-acetyl-D-glucal dimerises, and from the products the crystalline C–C linked disaccharide derivative 1,3,4,6-tetra-O-acetyl-2-C-(4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranosyl)-2-deoxy-β-D-glucopyranose has been isolated. Dimerisation is believed to occur by the trans-addition of one molecule of 1,4,6-tri-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranose to the double bond of another, and in agreement with this, evidence has been obtained that tri-O-acetyl-D-glucal initially rearranges in the presence of the catalyst (or thermally) to give mainly the 2,3-unsaturated isomer.

Journal ArticleDOI
TL;DR: In this article, two samples of soybean oil hydrogenated with copper-containing catalysts at 170 and 200 C were analyzed for their natural and isomeric fatty acids, and the double bond location in these fractions was determined by a microozonolysis-pyrolysis technique.
Abstract: Two samples of soybean oil hydrogenated with copper-containing catalysts at 170 and 200 C were analyzed for their natural and isomeric fatty acids. Methyl esters of the hydrogenated oils were separated into saturates, monoenes, dienes and trienes by countercurrent distribution between acetonitrile and pentane-hexane. Monoenes were further separated intocis- andtrans-isomers on a silver-saturated resin column. Double bond location in these fractions was determined by a microozonolysis-pyrolysis technique. The diene fraction was separated with an argentation countercurrent distribution method, and linoleate was identified by infrared, ozonolysis and alkaliisomerization data. The double bonds in thecis-monoenes were located in the 9-position almost exclusively. However, the double bonds in thetrans-monoene were quite scattered with 10- and 11-isomers predominating. About 86% to 92% of the dienes consisted of linoleate as measured by alkali isomerization. Other isomers identified as minor components includecis,trans andtrans, trans conjugated dienes and dienes whose double bonds are separated by more than one methylene group.

Journal ArticleDOI
TL;DR: In this article, the authors present data on the effect of structural and steric factors, catalysts and solvents on the mode and rate of condensation of activated olefins with amines, which indicate that the mechanisms of such condensations are to some extent general.
Abstract: The review presents data on the effect of structural and steric factors, catalysts, and solvents on the mode and rate of condensation of activated olefins with amines, which indicate that the mechanisms of such condensations are to some extent general. The considerable importance of the steric inhibition of the reactions is evidence in favour of the hypothesis of a polar transition state characterised by a rigid structure. Proton transfer involving a proton donor and (or) acceptor or, more rarely, the ejection of a negative ion (see the reactions of β-halogeno-olefins) plays a significant role in the stabilisation of the transition state. The sequence of relative activities of the olefins CH2=CHX is affected both by the polarising effect of the group X and the possibility of the delocalisation of the charges in the activated complex. Nevertheless the problems of the catalytic effect of proton-donating, alkaline, and particularly peroxidic additives are still not completely clear and require further study. The bibliography includes 266 references.

Patent
20 May 1969
TL;DR: In this paper, the authors propose a high-saliency approach for detecting a SURFACTANT with one or more POLYMERIZable vehicles, each containing at least one OLEFINIC double bond.
Abstract: HIGH SOLIDS AQUEOUS POLYMER EMULSIONS ARE PRODUCED BY FIRST ADMIXING A SURFACTANT WITH ONE OR MORE POLYMERIZABLE MONOMERS EACH CONTAINING AT LEAST ONE OLEFINIC DOUBLE BOND, TOGETHER WITH AN AMOUNT OF WATER CORRESPONDING TO BETWEEN ABOUT 6% AND ABOUT 25% BY WEIGHT BASED ON THE TOTAL WEIGHT OF MONOMER EMPLOYED. THE RESULTANT PRE-EMULSION IS THEN ADDED TO AN AQUEOUS MEDIUM AND POLYMERIZED IN THE REACTIVE PRESENCE OF A FREE RADICAL POLYMERIZATION CATALYST.





Journal ArticleDOI
TL;DR: An improved method is described for determination of the position of double bonds in polyenoic fatty acid methyl esters using partial reduction with hydrazine without prior hydrolysis to the free fatty acid.



Journal ArticleDOI
TL;DR: Isomeric 1-phenylheptenes mass spectra, investigating electron impact induced rearrangements of double bond, were analyzed in this article, showing that the electron impact induces rearrangement of double bonds.
Abstract: Isomeric 1-phenylheptenes mass spectra, investigating electron impact induced rearrangements of double bond

Patent
15 Jul 1969
TL;DR: In this paper, a new group of cyclists and cyclists are reported to be bearing at least one RADICAL having a POLYMERIZable double bond between the TermINAL CARBON ATOM and the PENULTIMATE CARBon ATOM.
Abstract: A NEW GROUP OF CYCLOTRI- AND CYCLOTETRAPHOSPHAZENE COMPOUNDS BEARING AT LEAST ON POLYMERIZABLE OLEFINIC MOIETY AND A METHOD OF ENHANCING PHYSICAL PROPERTIES SUCH AS FLAME RESISTANCE, SOLVENT RESISTANCE, HEAT RESISTANCE OR DEFORMATION RESISTANCE OF A VARIETY OF SUBSTRATES BY TREATMENT OF THE SUBSTRATE WITH IONIZING RADIATION AND CYCLOTRIPHOSPHAZENE OR CYCLOTETRAPHOSPHAZENE COMPOUNDS BEARING AT LEAST ONE RADICAL HAVING A POLYMERIZABLE DOUBLE BOND BETWEEN THE TERMINAL CARBON ATOM AND THE PENULTIMATE CARBON ATOM.

Journal ArticleDOI
TL;DR: In this paper, two general synthetic schemes to 5,8-isoquinolinediones were devised and the chemical and electrochemical behavior of these compounds were investigated, and the 1,4-addition reactions of these quinones with amines was shown to occur at the 7 position and a number of 7-amino-5, 8-isoline compounds were synthesized, and a linear correlation between the change in the half-wave potential of the quinone system (ΔE° 1/2) resulting from the introduction of different substitu