Cyclization of eleostearic acid

Paschke, Raymond; Wheeler, D. H.

doi:10.1007/bf02639941

Cited by 40 publications

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“…Our results on the structure of the cyclic monomer are similar to those of Paschkc and Wheeler (5) in that a) dehydrogenation followed by oxidation gave o-phthalic acid in similar yield to theirs (17 % against 20%); b) it is agreed that the postulated dialkylcyclohexadiene type of structure is present. We have however considered the mixture of isomers which constitutes the cyclic monomer in more detail and discuss this below.…”

Section: Discussionsupporting

confidence: 87%

“…Its ultraviolet spectrum, which is shown in Figure l(a), is very different from that recorded by Pasehke and Wheeler (5). 71 °, with p-toluenesulfonic acid as catalyst2 Some 115 g. of this ester were heated in a sealed evacuated ampoule for 41~ hrs.…”

mentioning

confidence: 65%

“…On distillation in a small falling-film molecular still at 105 °, this material yielded 10.0 g. of cyclic monomer, or 9% based on the original eleostearate. Its ultraviolet spectrum, which is shown in Figure l(a), is very different from that recorded by Pasehke and Wheeler (5). It had the following properties: Number of double bonds (Adams' catalyst in ethanol)~ 2.00 (cale.…”

mentioning

confidence: 68%

“…(cf. [5] ). The solution was acidified with diluted H~SO~ and extracted continuously with ether for ~ hr.…”

Section: Conversion Of the Cyclic Monomer To Orthophthalicmentioning

confidence: 99%

“…R ECENTLY PASCHKE AND WHEELER (5) studied the cyclic monomer obtained on polymerization of a 10% solution of mixed methyl eleostearates in methyl laurate at 250°C. for 48 hrs.…”

mentioning

confidence: 99%

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The chemistry of polymerized oils. VII. Cyclization of methyl beta‐eleostearate

Rivett

1956

J Americ Oil Chem Soc

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R ECENTLY PASCHKE AND WHEELER(5) studied the cyclic monomer obtained on polymerization of a 10% solution of mixed methyl eleostearates in methyl laurate at 250°C. for 48 hrs.Following our earlier work on the thermal dimer of methyl fl-eleostearate (1), we examined the cyclic monomer. From our previous investigations we had concluded that it was important in thermal polymerization studies to keep the reaction conditions as mild as possible, in order to minimize secondary changes. For this reason the cyclic monomer was separated from material which had only been heated at 180 ° for 4~ hrs.Experimental Preparation of Methyl fl-Eleostearate Cyclic Monomer. Methyl fl-eleostearate (m.p. 12.4 to 13.6°),E~m.-----1,850 in ethanol at 268 m~, was prepared by esterification from the acid, m.p. 71 °, with p-toluenesulfonic acid as catalyst2 Some 115 g. of this ester were heated in a sealed evacuated ampoule for 41~ hrs. at 180 °. Monomeric material (69 g.) was separated by repeated passages through a falling-film molecular still at 105 °. A solution of 66.2 g. of this distillate in 50 ml. of methanol was added at 40 ° to a solution of 330 g. of urea in 1,500 ml. of methanol. After 24 hrs. at room temperature the precipitate (which on decomposition with water gave 37.0 g. of oil) was filtered off, and the filtrate was concentrated to 800 ml. After two days the precipitate (which on decomposition with water gave 10.5 g. of oil) was removed, and the filtrate was concentrated to 500 ml. This solution was left at 5 ° over-night, and the precipitate was filtered off. On treatment with water the latter afforded 0.55 g. of oil. The filtrate, after removal of urea and methanol, gave 11.2 g. of ester. On distillation in a small falling-film molecular still at 105 °, this material yielded 10.0 g. of cyclic monomer, or 9% based on the original eleostearate. Its ultraviolet spectrum, which is shown in Figure l(a), is very different from that recorded by Pasehke and Wheeler (5). It had the following properties: Number of double bonds (Adams' catalyst in ethanol)~ 2.00 (cale. 2.00); C ~77.42% (calc. 78.03%); H 11.32% (cale. 11.04%). Conversion of the Cyclic Monomer to OrthophthalicAcid. Four grams (0.0134 mole) of this cyclic monomer were refluxed with 2.45 g. of N-bromosueeinimide (0.0134 mole) in 30 ml. of cal:bon tetrachloride for 3 hrs. The solution was cooled, and the solid succinimide (1.27 g.) was filtered off. The filtrate was evaporated under vacuum, and the residue was heated with 5 ml. of redistilled diethylaniline at 130 ° under nitrogen for 1 hr. to dehydrobrominate the diene to the benzene derivative. When cooled, the mixture set semi-solid. Water and hexane were added, and the ~Ester prepared from the acid by treatment with diazomethane in ether had E~c~.z 1,980, m.p. 14.0-15.1 °. Pure ester should have E~,,.= 2,060 based on E~n. = 2,161 for the acid (4).

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Section: Discussionsupporting

confidence: 87%

mentioning

confidence: 65%

mentioning

confidence: 68%

“…(cf. [5] ). The solution was acidified with diluted H~SO~ and extracted continuously with ether for ~ hr.…”

Section: Conversion Of the Cyclic Monomer To Orthophthalicmentioning

confidence: 99%

“…R ECENTLY PASCHKE AND WHEELER (5) studied the cyclic monomer obtained on polymerization of a 10% solution of mixed methyl eleostearates in methyl laurate at 250°C. for 48 hrs.…”

mentioning

confidence: 99%

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The chemistry of polymerized oils. VII. Cyclization of methyl beta‐eleostearate

Rivett

1956

J Americ Oil Chem Soc

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Studien über das Verhalten von Fettinhaltsstoffen bei der Raffination. 8. Mitt. Zur Bestimmung polymerer Fettsäuren in Rapsöl und deren Verhalten bei der Raffination

Franzke

Noske

Poth

1975

Nahrung

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1. Studies on rape-seed oil have shown that the determination of oxypolymers by means of the method according to Rost (determination of fatty acids insoluble in petroleum ether) yields unsatisfactory results. By way of contrast, the gravimetric determination (after isolation of the polymers via the non-urea adduct fatty acid methyl esters and thin-layer chromatographic separation), as proposed by the authors, permits to obtain results of good reproducibility and to determine thermopolymers and oxypolymers separately. 2. During the refining of rape-seed oil, it was observed that its polymer content decreased considerably on bleaching, and increased on deodorizing.

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Alkalicyclisierung langkettiger Triencarbonsäuren

Sagredos

Mikusch

Wolf

1971

Justus Liebigs Ann. Chem.

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Je zwei Triencarbonsauren rnit isolierten Doppelbindungen (9c.12c.15c-bzw. 9f.12f.15f-Octadecatriensaure 1 bzw. 5) sowie rnit konjugiertem System (9C.11'.13t-bzw. 9"ll'. 13'-Octadecatriensaure 4 bzw. 6) werden bei 180" rnit KOH in Athylenglykol partiell cyclisiert. Dabei entsteht aus 1 primar das Cyclohexadien-Derivat 3 (n = 3), wahrend die Triene 4 und 6 bzw. 5 rnit zentraler trans-Doppelbindung zu einem Gemisch von 3 mit n = 3, 4 und 5 bzw. rnit n = 2, 3 und 4 cyclisiert werden. Das Ergebnis deutet auf einen MehrzentrenMechanismus fiir den RingschluR, dem eine ionisch ablaufende Isomerisierung zu einem cyclisierungsfahigen Konjutrien-System mit zentraler cis-Doppelbindung vorangeht. -Cyclisierung von 1 bei 220" rnit NaOH in Diathylenglykol liefert ebenfalls 3 rnit PropylSeitenkette (n = 3) als Hauptkomponente. Die drei Carbonsauren ohne zentrale cis-Doppelbindung ergeben jedoch infolge einer prototropen Wanderung des bereits vorhandenen bzw. in 5 bei der Isomerisierung entstehenden Konjutrien-Systems eine breitere Isomeren-Verteilung. Alkali Cyclisation of Long-Chain Trienoic Carboxylic AcidsTwo trienoic carboxylic acids with isolated double bonds, the 9c,12c,15c-(1) and the 9f,12f,15t-octadecatrienoic acid (9, as well as two of such acids with conjugated system, the 9c,11f,13f-(4) and the9',1 1f,13'-octadecatrienoicacid (6) are partiallycyclised at 180" withKOH in ethylene glycol solution. In this reaction 1 yields primarily the cyclohexadiene derivative 3 with n = 3, whereas the trienes 4 and 6, or 5 with a central trans double bond are cyclised to a mixture of 3 with n = 3, 4 and 5, or n = 2, 3 and 4, respectively. The result indicates a polycentric mechanism for the ring closure which is preceded by an ionic isomerisation yielding a cyclisable conjutriene system with central cis-double bond. -Cyclisation of 1 at 220" with NaOH in diethylene glycol, yields again compound 3 with propyl side chain (n = 3) as principal component. However, the three carboxylic acids without central cis-double bond yield a wider isomer distribution due to a prototropic migration of the conjugated triene system already present or, as in 5, being formed during isomerisation. *) Vortrag anlaDlich der GDCh-Tagung, Univ. Hamburg 1969.

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Cyclization of eleostearic acid

Cited by 40 publications

References 16 publications

The chemistry of polymerized oils. VII. Cyclization of methyl beta‐eleostearate

The chemistry of polymerized oils. VII. Cyclization of methyl beta‐eleostearate

Studien über das Verhalten von Fettinhaltsstoffen bei der Raffination. 8. Mitt. Zur Bestimmung polymerer Fettsäuren in Rapsöl und deren Verhalten bei der Raffination

Alkalicyclisierung langkettiger Triencarbonsäuren

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