A study of 1,5-hydrogen shift and cyclization reactions of an alkali isomerized methyl linolenoate

Matikainen, Jorma; Kaltia, Seppo; Ala-Peijari, Maija; Petit-Gras, Ninna; Harju, Kirsi; Heikkilä, Jaakko; Yksjärvi, Raija; Hase, Tapio

doi:10.1016/s0040-4020(02)01513-2

Cited by 22 publications

(16 citation statements)

References 14 publications

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“…o-(oalkylphenyl)octadecanoic acids were first detected during the heating of modern cooking oils containing triunsaturated fatty acyl lipids in experiments employed to determine the potential toxicity of frying oils (Michael 1966(Michael , 1996. More recently, o-(o-alkylphenyl)octadecanoic acids have been shown to form from methyl linolenic acid through laboratory thermal degradation studies (Matikainen et al 2003). Figure 12 summarizes the reaction scheme leading to their formation.…”

Section: O-(o-alkylphenyl)alkanoic Acidsmentioning

confidence: 99%

Experimental approaches to the interpretation of absorbed organic residues in archaeological ceramics

Evershed¹

2008

World Archaeology

190

169

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All scientific investigations require experimentation to test hypotheses and support interpretations. Thus, experimental studies are an indispensable aspect of investigations of organic residues from archaeological ceramics. Experimental methods have been applied to provide insights into factors relating to vessels use and burial. Studies relating to vessel use have used replica vessels, ceramic chips and powder to investigate both physical and chemical phenomena relating to organic residue deposition and transformations. Ethnographic vessels are employed to bridge a practical gap, providing insights into the impacts of long-term vessel use that would be impossible to address in laboratory experiments. By combining such studies we have provided important insights into the chemical compositions observed and prompted searches for novel marker compounds that might otherwise have been overlooked. Potsherds impregnated with organic residues provide substrates for investigating the impacts of burial on chemical and stable isotopic compositions.

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Section: O-(o-alkylphenyl)alkanoic Acidsmentioning

confidence: 99%

Experimental approaches to the interpretation of absorbed organic residues in archaeological ceramics

Evershed¹

2008

World Archaeology

190

169

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“…ω‐( o ‐Alkylphenyl)octadecanoic acids were first detected during the heating of modern cooking oils containing triunsaturated fatty acyl lipids in experiments employed to determine the potential toxicity of frying oils (Michael 1966a,b). More recently, ω‐( o ‐alkylphenyl)‐octadecanoic acids have been shown to form from methyl linolenic acid through laboratory thermal degradation studies (Matikainen et al 2003). Figure 1 summarizes the reaction scheme leading to their formation; it proceeds with alkali isomerization (1) and, following a 1,5 hydrogen shift (2) , trans / cis isomerization occurs (3) , to yield a fully conjugated fatty acid.…”

Section: Introductionmentioning

confidence: 99%

“… Scheme (after Hansel et al 2004 ) showing the formation of ω‐( o ‐alkylphenyl)alkanoic acids from cis,cis,cis ‐9,12,15‐octadecatrienoic acid via alkali isomerization ( 1 ), a 1,5 hydrogen shift ( 2 ) and then either a cis/trans isomerization ( 3 ) or a 1,7 hydrogen shift ( 5 ) followed by an IMDA reaction and aromatization ( 4 ). The reaction can occur at 270°C over 17 h ( Matikainen et al 2003 ). …”

Section: Introductionmentioning

confidence: 99%

Experimental Evidence for the Processing of Marine Animal Products and Other Commodities Containing Polyunsaturated Fatty Acids in Pottery Vessels*

et al. 2008

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ω -( o -Alkylphenyl)alkanoic acids are known to form in vitro from triunsaturated fatty acids following protracted heating. These compounds have recently been identified in absorbed lipid extracts obtained from archaeological pottery vessels, providing a potentially valuable new class of indicator for the processing of commodities, such as marine oils, which contain high abundances of polyunsaturated fatty acids. Experiments were conducted to assess whether ω -( o -alkylphenyl)alkanoic acids form when pure compounds and complex triacylglycerol mixtures are heated with a fired clay. The results demonstrate that ω -( oalkylphenyl)alkanoic acids are only produced following heating of unsaturated fatty acids (tri-, di-and monounsaturated species) or complex unsaturated fatty acyl lipids at around 270 ° C. Heating saturated fatty acyl lipids does not yield ω -( o -alkylphenyl)alkanoic acids. Thus, when searching for evidence for the processing of marine derived animal fats in archaeological pottery vessels, it is essential that: ω -( o -alkylphenyl)alkanoic acids of carbon length C 18 and C 20 should be present, ideally with C 22 also detectable (if only in trace abundances), together with at least one of the three isoprenoid fatty acids (phytanic, pristanic or 4,8,12-tetramethyltridecanoic acid).

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“…Owing to the difficulties in obtaining pinolenic acid in quantity in a pure state, its chemistry has been little studied when compared to linolenic or linoleic acids. We reported [1] earlier the isolation of 1a from tall oil by an iodo-lactonization method, its alkali isomerization and the synthesis of many of the isomers [2] and their intramolecular Diels-Alder cyclization reactions [3,4].…”

Section: Introductionmentioning

confidence: 99%

“…We have for years successfully used the exceptionally simple and robust K 2 CO 3 mediated aqueous Wittig procedure [8] for the synthesis of various alkali isomerization products of pinolenic [2] and linolenic [4] acid esters, as well as other straight chain compounds [9,10] capable of producing hexahydroindenes via intramolecular DielsAlder reactions. We now report the results of using 2 as the ylide generating precursor in the potassium carbonate mediated one-pot aqueous double Wittig synthesis of methylene skipped cis diene and triene structures, and show that the obstacles just mentioned may be overcome to an extent.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Ethyl 5Z,9Z,12Z‐octadecatrienoate (ethyl pinolenate) and Methyl 12Z,15Z‐octadecadienoate

Kaltia

Matikainen

Ala-Peijari

et al. 2008

J Americ Oil Chem Soc

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Pinolenic acid (5Z,9Z,12Z-octadecatrienoic acid, 1a), one of the most abundant trienoic fatty acids in nature, is very difficult to obtain in quantity in a pure state from the highly complex mixture of unsaturated tall oil fatty acids. For this reason its chemistry has been little studied when compared to linolenic or linoleic acids. A simple synthesis of esters of 1a and of 12Z,15Z-octadecadienoic acid 3 using the one pot double Wittig procedure is described here. The products of double Wittig reactions were purified by argentation chromatography, and their structural purity was established by 1 H-, 13 C-NMR and 2D-NMR spectroscopies.

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A study of 1,5-hydrogen shift and cyclization reactions of an alkali isomerized methyl linolenoate

Cited by 22 publications

References 14 publications

Experimental approaches to the interpretation of absorbed organic residues in archaeological ceramics

Experimental approaches to the interpretation of absorbed organic residues in archaeological ceramics

Experimental Evidence for the Processing of Marine Animal Products and Other Commodities Containing Polyunsaturated Fatty Acids in Pottery Vessels*

Synthesis of Ethyl 5Z,9Z,12Z‐octadecatrienoate (ethyl pinolenate) and Methyl 12Z,15Z‐octadecadienoate

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