BF₃−MeOH: A single reagent for ozonolysis of monoethylenic unsaturation

Abstract

Ozonolysis of monoethylenic fatty acids in BF3−MeOH, or in MeOH with subsequent addition of BF3−MeOH, gives oxidative fission acid products as methyl esters in a nominal 100% yield and a purity ≥98% of principal acid products. The in situ esterification step requires ca. 1 hr of heating with 7 or 14% BF3, but other time requirements are much less, totalling no more than half an hour. Different liquid phases for open‐tubular gas liquid chromatography of some products are compared.

Evidence for the synthesis of the multi-positional isomers of monounsaturated fatty acid in Methylococcus capsusatus by the anaerobic pathway

“…The saponified mixture was acidified and extracted with hexane. Oxidative ozonolysis and analysis of the resulting dicarboxylic acids was used to determine the double bond positions [15]. The methylated fatty acids were separated by gas chromatography using a 20% DEGS column as 165 °C and a Varian aerograph equipped with a TC detector and collection port.…”

“…Individual fatty acid peaks were collected in glass U-tubes and transferred to scintillation vials for counting or to test tubes for ozonolysis. Oxidative ozonolysis and analysis of the resulting dicarboxylic acids was used to determine the double bond positions [15]. After addition of the C s to C13 carrier dicarboxylic fatty acids (Larodan Fine Chemicals and Aldrich Chemical Co.), ozonolysis was carried out for 30 min in 14% BF3/methanol using a Supelco micro-ozonizer apparatus, and then the tubes were sealed and heated at 100°C for 60 rain.…”

Hydrogenation of a menhaden oil: I. Fatty acid and C20monoethylenic isomer compositions as a function of the degree of hydrogenation

“…The recovered monoethylenic fatty acid methyl esters were separated into cis and trans isomers by AgNO3-TLC (14). Each fraction was then ozonized in BF 3 / MeOH and the resulting monoesters and diesters analyzed on a BDS column (15,16).…”

Identification of double bond position in lipids: From GC to OzID

“…Since that time it has been the method of choice for the analysis of FAs from most sources including animal [37] and human tissues [38], plants [39] and food [40]. While GC is not capable of identifying the position of all double bonds within a fatty acid (without prior degradation such as permanganateperiodate oxidation [41] or ozonolysis [42]) it can resolve FAs that contain positional isomers of the double bond closest to the methyl end of the carbon chain (sometimes called the -end). An example Fig.…”