Methyl Malvalate Research Articles

Preparation of malvalic and sterculic acid methyl esters from Bombax munguba and Sterculia foetida seed oils

AbstractA method has been developed for the preparation of highly pure malvalic (cis‐8,9‐methyleneheptadec‐8‐enoic) and sterculic (cis‐9,10‐methyleneoctadec‐9‐enoic) acid methyl esters starting from Bombax munguba and Sterculia foetida seed oils. The methyl esters of these oils were prepared by sodium methylate‐catalyzed transmethylation followed by cooling (6°C) the hexane solution of crude methyl esters and separation of insoluble fatty acid methyl esters by centrifugation in the case of B. munguba and by column chromatography in the case of S. foetida. Subsequently, the saturated straight‐chain fatty acid methyl esters were almost quantitatively removed by urea adduct formation. Finally, methyl malvalate and methyl sterculate were separated from the remaining unsaturated fatty acid methyl esters, in particular methyl oleate and methyl linoleate, by preparative high‐performance liquid chromatography on C18 reversed‐phase using acetonitrile isocratically. Methyl malvalate and methyl sterculate were obtained with purities of 95–97 and 95–98%, respectively.

Solubilities of six cottonseed oil fatty acid methyl esters in methanol

AbstractSolubilities of six cottonseed oil fatty acid methyl esters in metha‐nol have been determined. The esters were: methyl oleate, methyl linoleate, methyl malvalate, methyl dihydromalvalate, methyl sterculate and methyl dihydrosterculate. The solubility/temperature data are presented in graphical and tabular form.

Gas chromatographic analysis of cyclopropenoid acids in cottonseed oils

AbstractA gas chromatographic method of analysis for cyclopropenoid acids in cottonseed oil, as the methyl esters, is described. With a glass column packed with a methyl silicone substrate on an inert support, methyl sterculate and methyl malvalate can be chromatographed without decomposition. Although methyl malvalate was not well resolved from methyl linoleate, it could be quantitated accurately at concentrations as low as 0.03% by a peak‐height method. Quantitation can be done manually with an internal standard, or with a data system without an internal standard. The method does not require calibration with a cyclopropenoid acid standard, i.e., it is a primary method. Results compare favorably with those obtained by HBr titration. Less than 1 mg of oil is required for an analysis.

Separation of methyl malvalate from methyl sterculate

AbstractMethyl malvalate and sterculate, labile and differing by a single methylene, are difficult to separate completely. They have been separated in our laboratory by high vacuum spinning band distillation. Each of these fatty esters has been prepared completely free of the other.

Some thermal properties of methyl malvalate, methyl sterculate, and their dihydro derivatives

Abstract and SummaryMethyl esters of cyclopropene acids, malvalic and sterculic, and their dihydro derivatives, were highly purified and examined for melting points, poly‐morphic behavior, heats of fusion, and dilatometric behavior. Results revealed that the quickly chilled forms of the unsaturated methyl esters underwent a rapid monotropic transformation. The dihydro derivatives exhibited no detectable polymorphism. The melting dilation for methyl malvalate was signifi‐cantly below the previously reported dilations of other fatty acid methyl esters.

Mass spectra of methyl sterculate and malvalate and 1,2-dialkylcyclopropenes

The mass spectra of 1,2-dipropyl-, 1,2-dipentyl-, 1,2-dihexyl-, 1,2-diheptyl-, and 1,2-dioctyl-cyclopropene, methyl malvalate, methyl sterculate, malvalyl alcohol, 1,2-dipropyl-, 1,2-dipentyl-, and 1,2-dihexylcyclopropene-3-carboxylic acid, and methyl-9,10-(carbethoxymethano)-9-octadecenoate are presented. A noticable feature of the 1,2-disubstituted cyclopropene spectra is the total absence of a cyclopropenium ion. The cyclopropenes with a carboxyl group in the 3-position yield cyclopropenium ions in the mass spectra. β-Cleavage to a allylic ion appears to be important.

Mass spectrometry of the silver nitrate derivatives of cyclopropenoid compounds

1,2-dihexylcyclopropene, 1,2-diheptylcyclopropene, 1,2-dioctylcyclopropene, methyl malvalate, and methyl sterculate have been reacted with silver nitrate in methanol to form the corresponding methoxy and ketone derivatives. GLC, IR, and MS data are presented. The mass spectra and a possible method for determining the cyclopropene ring position are discussed.

Synthesis of 1,2-dialkylcyclopropenes, methyl malvalate, and sterculate

Synthesis of 1,2-dialkylcyclopropenes, methyl malvalate, and sterculate

High resolution NMR for purity determination of cyclopropenoid concentrates

AbstractHigh resolution nuclear magnetic resonance is proposed as a method for assaying the cyclopropenoid concentration of methyl sterculate and methyl malvalate concentrates. Spectra obtained on a 220 MHz instrument are analyzed and compared with that obtained on a 60 MHz instrument. Calculation of cyclopropene concentration based on methoxy protons and cyclopropene protons is discussed.

Syntheses of methyl malvalate and methyl 5-6-methano-5-undecenoate

This invention relates to the preparation of methyl malvalate, methyl 5,6-methano-5-undecenoate and the preparation of some new intermediates. Malvalic acid, the major cyclopropene component in cottonseed oil, has been synthesized. When 1-chloro-7-hexadecyne reacts with diazoacetic ester in the presence of copper bronze, the ester of 1-chloro-7,8-carboxymethano-7-hexadecene is formed. Treating the corresponding acid chloride with zinc chloride causes loss of carbon monoxide. Either sodium borohydride or lithium aluminum hydride reduces the resulting cyclopropenium compound to 1-chloro-7,8-methano-7-hexadecene. Replacing the chloro group with cyano yields malvalonitrile, which can be converted to methyl malvalate. An analogous sequence of steps has been applied to 1-chloro-4-decyne to produce methyl 5,6-methano5-undecenoate. An alternate synthesis of methyl malvalate starts by using 1-chloro-7-hexadecyne as the precursor for methyl 8heptadecynoate. This acetylenic ester is converted to 8,9carboxymethano-8-heptadecenoic acid, the diacid chloride of which decarbonylates selectively in the presence of metallic chlorides to form the cyclopropenium-acid chloride. After esterification the resulting cyclopropenium-ester is reduced with borohydride to methyl malvalate.

Syntheses of labelled methyl malvalate

Practical syntheses of homogeneous methyl malvalate, adaptable for inserting radiocarbon at positions 1, 9, 10, and ring CH2, are described.

Preparation of methyl malvalate fromSterculia foetida seed oil

AbstractMethyl malvalate has been prepared from mixed methyl esters ofSterculia foetida seed oil fatty acids by reversed‐phase liquid‐liquid partition chromatography, and confirmatory evidence adduced for its structure.