Untersuchungen über die Autoxidation verzweigter Olefine. I,Autoxidation von 2-Methylalk-1-enen und 2-Methyalk-2-enen

Studies on the Autoxidation of Branched-chain Olefins. I. Autoxidation of 2-Methylalk-1-enes and 2-Methylalk-2-enes The products of the autoxidation of 2-methylpent-1-ene, 2-methylpent-2-ene, 2-methylhex-1-ene, 2-methylhex-2-ene, 2,4,4-trimethylpent-1-ene, and 2,4,4-trimethylpent-2-ene were analyzed by gas chromatography. The identification of the products corresponding to the individual peaks was possible by comparison with authentic substances or by preparative gaschromatographic separation and n.m.r.-spectroscopy of the isolated samples. In this way not only the epoxides and the products of the oxidative cleavage of the CC-double bond but also the allylic alcohols formed by LiAlH₄-reduction of the oxidation mixtures could be identified and analyzed. From the results the compositions of the original oxidation mixtures were calculated.     

Untersuchungen über die Autoxidation verzweigter Olefine. V. Allgemeine Gesetzmäßigkeiten

Studies on the Autoxidation of Branched-chain Olefins. V. General Regularities The rates of oxidation and the yields of epoxides of unbranched and branched olefins are discussed. The rates of oxidation increase with the increasing number of alkyl groups bound at the CC-double bond. Epoxide yields show no simple dependence on the olefin structure. The allyl radicals formed as intermediates of olefin oxidation are preferably attacked by oxygen either at the less hindered end (in the case of nonbranched olefins) or at the higher substituted end (in the case of branched olefins) of the allylic system. The reasons for these regularities are discussed. Where Z/E-isomerism is possible, the (E)-configuration in allylic radicals is more stable than the (Z)-configuration, and therefore the (E)-forms of the allylic hydroperoxides are preferably formed.     

Kinetische Untersuchungen über die Autoxidation von Olefinen

Kinetic Studies on the Autoxidation of Olefins The oxidabilities \documentclass{article}\pagestyle{empty}\begin{document}$ {{{\rm k}_{\rm p} } \mathord{\left/ {\vphantom {{{\rm k}_{\rm p} } {\sqrt {2{\rm k}_{\rm t} } }}} \right.\kern-\nulldelimiterspace} {\sqrt {2{\rm k}_{\rm t} } }} $\end{document} at 50°C were determined for 37 olefins, using chlorobenzene as the solvent and azodiisobutyronitril as the initiator. In the group of acyclic aliphatic olefins the oxidability rises with increasing number of alkyl groups bound to the double bond. This is also true for cyclic olefins, but in this case the ring size has also a great influence on the oxidability. So the oxidability decreases from five-ring to eight-ring cycloolefins. Particularly high oxidabilities are found in the case of olefins in which a phenyl group is attached directly to the C C-double bond.     

Kinetische Untersuchungen über die Addition von Halogenwasserstoffen an Olefine

Kinetic Studies on the Addition of Hydrogen Halides to Olefins The relative rates of the reactions of olefins with hydrogen bromide and iodide were determined in acetic acid solution. The kinetic data of the substituted styrenes were correlated by means of the Hammett equation, those of the open-chain aliphatic olefins were correlated by means of the three- and the five-parameter Taft equations. All correlations show the transition state to be similar to an open carbenium ion.     

Untersuchungen über die Autoxidation der isomeren n-Octene

Studies on the Autoxidation of the Isomeric n-Octenes The products of autoxidation of the positionally and sterically isomeric n-octenes were analyzed by gaschromatography. 22–37% of the gaschromatographically detected compounds were epoxides, 2–9% were products of oxidative cleavage of the CC-double bond, and 50–70% were allylic oxidation products. Independently of the stereochemistry of the starting olefins mixtures of the corresponding cis- and trans-epoxides were always formed; in the oxidation products of cisoctenes more cis-epoxides are present than in the oxidation products of trans-octenes. The composition of the octenol mixtures, obtained by preparative gaschromatographic isolation from the sodium sulphite reduction products of the oxidates, could be determined by ¹³C-n.m.r. analysis. All expected positional isomers are formed. The trans-octenes almost exclusively yield the trans-octenols; from the cis-octenes the octenols with the double bond in the original position are formed as mixtures of the corresponding cis- and trans-isomers, but the octenols with shifted double bonds almost exclusively are present in their transforms. The stereochemical results are discussed on the basis of the lifetime and the conformational or configurational stability of the intermediate radicals. In connection with the ¹³C-n.m.r.-investigation of the reaction products increments for the shift of ¹³C-signals by introduction of hydroperoxy, hydroxy, and carbonyl groups in allylic position of olefins were derived.     

Über die Autoxidation einiger monocyclischer Olefine

Studies on the Autoxidation of Some Monocyclic Olefins The autoxidations of cyclopentene, cyclohexene, cycloheptene, cyclooctene, cycloocta-1,5-diene, 1-methylcyclopentene, 1-methylcyclohexene, 1-methylcycloheptene, 1-methylcyclooctene, methylene cyclopentene, and methylene cyclohexene with pure oxygen under normal pressure were studied. The epoxides formed were determined gaschromatographically. In most cases also the products of allylic oxidation were analyzed and their structures elucidated after reduction to the corresponding allyl alcohols. The portions of high boiling or polymeric products which could not be detected gaschromatographically and also the real yields of epoxides were determined by balance experiments in the presence of inert internal standards.     

Über die Autoxidation von Vinylcylopentan,Vinylcyclohexan und 4-Vinylcyclohex-1-en

Autoxidation of Vinylcyclopentane, Vinylcyclohexane, and 4-Vinylcyclohex-1-ene The title olefins were oxidized with molecular oxygen at 75–80°C. About 40% of the oxygen absorbed were found by iodometric titration as peroxidic oxygen. The reaction products were analyzed by a combination of chemical methods, gas chromatography, and ¹³C-n.m.r.-spectroscopy. Vinylcyclopentane and vinylcyclohexane are attacked preferably at the tertiary allylic C-H-bonds giving almost equimolar mixtures of the corresponding allylisomeric hydroperoxides. In the case of 4-vinylcyclohex-1-ene the C-H-bonds in position 6 are preferably attacked, but products of attack on the other allylic C-H-bonds also could be identified. In all cases the amount of products which could not be detected gaschromatographically was determined by balance experiments in the presence of an internal standard.     

Untersuchungen über die Lipide von Kartoffeln

Investigations on the Lipids of Potatoes Gas chromatographic investigations on the fatty acid composition of the total lipids of freeze-dried potato showed that 90% of the fatty acids consist of linolenic, linoleic, palmitic and stearic acids. In all, 31 different fatty acids were detected and identified. Noticeable amounts of odd-chain fatty acids and those having more than 20 C-atoms (up to C₃₀) were found. Eight different varieties of potato were investigated. Difference in the fatty acid composition of the individual varieties was not appreciable. Experiments on the group separation of lipids showed that they contain a large amount of phospholipids (especially lecithin and cephalin). Appreciable amounts of triglycerides were also found, however, the sterol esters, sterols and free fatty acids were present to a lesser extent.     

Untersuchungen über die Autoxydation von Margarine

Investigations on the Autoxidation of Margarine The authors investigated the influence of storage temperature, packing and of the quality of dispersion on the oxidative stability of margarine. The oxidative stability of margarine is improved with increasing fineness of the dispersion. The autoxidation can be prevented to a great extent by employing low storage temperature and suitable packing material. Packing materials containing traces of heavy metals promote the autoxidation in the upper layer of margarine.     

Untersuchungen über die Wirksamkeit von Konservierungsmitteln in anionaktiven Tensiden II

Investigations on the Efficacy of Preserving Agents in Anion Active Surfactants II The authors investigated the preserving action of p-chloro-m-cresol and of pHB-methyl/ethyl ester combination (1 + 1) in solutions of anion active surfactants. The preservatives were employed at two different concentrations. The concentration of the surfactants (lauryl sulfate and protein-fatty acid condensate as sodium, potassium and triethanolamine salts) was varied from 0.1 to 10.0 g/100 g. The pH of the solutions was 7. The deactivation of the preservatives investigated here by the anion active surfactant occurs only after a certain ratio of surfactant to preservative is reached. Under this ratio the preservatives are fully effective; above this, however, are the preservatives deactivated.     

Untersuchungen zur Sulfochlorierung von Paraffinen. II. Untersuchungen über die Reaktion von aliphatischen Sulfochloriden mit Nucleophilen

Studies on the Sulphochlorination of Paraffins. II. Studies on the Reaction of Aliphatic Sulphochlorides with Nucleophiles The reaction of sterically pure cis- and trans-4-methyl-cyclohexyl sulphochlorides with dimethyl amine, natrium methylate, and natrium phenolate in each case gives mixtures of the cis- and trans-isomers of the corresponding derivatives of 4-methylcyclohexyl sulphonic acid, which could be separated by gas chromatography. Reaction of cis- and trans-4-methyl-cyclohexyl sulphochlorides with potassium fluoride in DMF/H₂O gives 4-methylcyclohexyl sulphofluoride; the cis- and trans-forms of this compound could not be separated by gas chromatography. If n-propyl or isopropyl sulphochloride react with potassium fluoride in DMF/D₂O; the sulphofluorides which are formed do not contain deuterium. Evidently the reaction of primary and secondary aliphatic sulphochlorides with basic nucleophiles proceeds by an elimination-addition-mechanisms with sulphenes as short-living intermediates, but the reaction with fluoride ions proceeds by an addition-elimination-mechanism.     

Untersuchungen über die toxikologischen Eigenschaften von Waschmittelenzymen

Investigations on the Toxicological Properties of Enzymes Used in Washing Agents Enzymes used in washing agents and enzyme-containing washing agents were tested in animal experiments for their general and local tolerance. The results of these investigations confirm that enzymes employed in washing agents are not toxic. The amounts of enzymes that are added to washing agents do not alter the local tolerance of such products. Similar observations were made in dermatological investigations on testpersons. From the results, it may be concluded that enzyme-containing washing agents do not present any hazard to the health of consumers. The same is also true for allergic reactions. Enzymes used in washing agents do have histamine-and kinin-liberating properties, however, only at such concentration-ranges that are insignificant for the practice.     

Studien über die Autoxidation von 1-Phenylbuta-1,3-dien und 2-Phenylbuta-1,3-dien

Studies on the Autoxidation of 1-Phenylbuta-1,3-diene and 2-Phenylbuta-1,3-diene Hydrogenation of the polymeric peroxides formed during the autoxidation of 1-phenylbuta-1,3-diene ( 1 ) and 2-phenylbuta-1,3-diene ( 10 ) at 50°C in an autoclave yielded 1-phenylbutane-3,4-diol ( 5 ) and 2-phenylbutane-1,4-diol ( 12 ), respectively. The LiAlH₄ reduction of 1-phenylbuta-1,3-diene oxidate (50°C) yielded cinnamyl alcohols ( 4 ) as a major product. The oxygen-containing polymeric products formed along with Diels-Alder dimers during the oxidation of the title substances at 140°C showed no degradation after subjecting to hydrogenation and are therefore considered as polyethers.     

Untersuchungen über die Haltbarkeit der Struktur von Margarine

Studies on the Structural Stability of Margarine In certain cases the stability of the structure of margarine is considerably impaired due to recrystallization of the solid phase. Microscopic studies, differential thermoanalysis and chemical methods were employed in order to gather an insight in the relationship between the composition of margarine fats and the occurrence of such structural alterations.     

Untersuchungen über die Verseifungsfarbzahl

Studies on the Saponification Colour Number Oxidized fats give yellow to brown solutions on saponification with alcoholic potassium hydroxide. Studies reported here were directed towards determining the causes of such reactions. The results indicate that at least two multiple bonds which are conjugated in relation to the carbonyl group, or a α,β-dicarbonyl group give a strong reaction on heating with alcoholic potassium hydroxide. It is shown that under certain conditions of reaction the saponification colour number is suitable as a measure for the degree of oxidation of heated fats. The method employed is described.