Reaktion ungesättigter Fettsäuren mit Quecksilber(II)‐acetat; Anwendung für präparative Trennungen, I

Abstract

Die Umsetzung von Methylestern ungesättigter Fettsäuren mit Quecksilber(II)‐acetat in Methanol führt zu relativ beständigen Addukten. Der geschwindigkeitsbestimmende Schritt der Reaktion folgt dem Gesetz der 2. Ordnung. Diskontinuierliche Gegenstromverteilung ermöglicht nach der Adduktbildung ungesättigter Fettsäuremethylester deren nahezu quantitative Abtrennung aus Gemischen mit gesättigten Fettsäureestern. Die Trennung cis‐trans‐isomerer ungesättigter Fettsäuren über ihre Quecksilberaddukte gelingt ebenfalls mit hohem Reinheitsgrad und befriedigender Ausbeute auf Grund ihrer unterschiedlichen RG. cis‐trans‐Isomerisierung wurde hierbei bisher nur in sehr geringem Ausmaß beobachtet.

Thalictrum polycarpum Fatty Acids—A New Class of Fatty Acids from Vegetable Seed Oils*

“…Infrared spectral analysis indicated 75% isolated f rans-unsaturation. The C¡ ¡¡-monoene isomers were reacted with mercuric acetate in methanol (Jantzen and Andreas, 1959), and the addition compounds were resolved from the palmitic acid by solvent partitioning; however, no attempt was of acetone/g of free acid).…”

Lipid Alterations in Euglena gracilis Cells During Light-induced Greening*

“…An ethylene glycol succinate column at 173°was used with argon serving as the mobile phase. The unsaturated methyl ester fraction was isolated as the methoxy mercuri-acetate adduct (Jantzen and Andreas, 1959) and chromatographed separately. As a further aid to identification, the unsaturated fraction of methyl esters of the fatty acids was reduced and rechromatographed.…”

Argentation in Countercurrent Distribution to Separate Isologues and Geometric Isomers of Fatty Acid Esters.

“…Methyl esters have also been separated after reaction with a limited amount of mercuric acetate. Cis isomers react more rapidly than trans with mercuric acetate, and unreacted trans esters can be separated from the adduct by countercurrent distribution (CCD) (8) . Lucas, Moore, and Pressman (12) pointed out that compounds with cis double bonds form complexes with silver ion to a greater extent than do their trans isomers. I n 1952, Nichols (IS) applied this information to a study of methyl oleate and methyl elaidate.…”

“…Cis isomers react more rapidly than trans with mercuric acetate, and unreacted trans esters can be separated from the adduct by countercurrent distribution (CCD) (8).…”