Synthesis of naturally occurring furan fatty acids

Abstract

Figure 2. Newman projections of a concerted reaction.could be separated from an almost equal quantity of an inseparable mixture of 2b and acetates lg and lh. The 300-MHz NMR analyses clearly showed that >50% of the mixed fraction obtained from la and <50% of the mixed fraction from lb were cyclopropyl acetates lg and lh. Time and Temperature Studies of the Acetolysis Reaction.Solutions of 3 pL of compound in 10 µL of glacial acetic acid were submitted to various temperature and time intervals. They were then quenched in aqueous sodium bicarbonate solution, extracted, and analyzed by thin-layer chromatography or analytical highpressure LC using a suitable hexane-ether elution system. In this way it was found that at 25 °C la and lb were stable to glacial acetic acid for up to 8 h.The product ratio of acetates obtained by heating either la or lb in glacial acetic acid at 110-11 °C over intervals between 10 min and 16 h were not significantly different.The products 2a and 2b were not interchanged significantly over a period of 24 h at 110 °C in glacial acetic acid.(U)-3-Ethylidenecyclohexanol 3,5-Dinitrobenzoate. A solution of 290 mg of 2a and 180 mg of potassium hydroxide in 4 mL of methanol was refluxed under nitrogen for 1.5 h. The reaction mixture was concentrated to dryness and treated with water. The product was extracted into ether, washed with water (4X), dried (MgS04), and isolated as a liquid. This material was eluted through 18 g of silica gel to give 88 mg of 3-ethylidenecyclohexanol:

Furan fatty acid as an anti-inflammatory component from the green-lipped mussel Perna canaliculus

“…To examine the anti-inflammatory activity, a sufficient amount of pure material was required. Although several groups previously reported the synthesis of F-acid (43)(44)(45)(46)(47)(48)(49), the synthetic route required many steps. To prepare these fatty acids easily, a shark metabolite was selected as the starting material, because sharks are commercially available for consumption in the northeast area of Japan.…”

The Preparation of 2,3,5-Tri- and 2,3-Disubstituted Furans by Regioselective Palladium(0)-Catalyzed Coupling Reactions: Application to the Syntheses of Rosefuran and the F5 Furan Fatty Acid

“…The total yield amounted to of 2-alkynyl-substituted 3-bromofurans such as 5, 11, and 55%. In contrast, under the same reaction conditions furan 20 gave that had been previously prepared by Schlenk et al from methyl 3-methylfuran-2-carboxylate in 5 steps (3% yield) [31] a mixture of starting material 20, hydrodebrominated product, and the desired methyldebrominated product 21 in a and by Marson et al from cyclodecanone in 6 steps (13% yield). An alternative approach will be dissp 3 -carbon atom in 2-position of 8e not only slows down cussed in section 5. the oxidative addition but also facilitates hydrodebromination, possibly by retarding the transmetalation and/or reductive elimination step.…”

The Preparation of 2,3,5-Tri- and 2,3-Disubstituted Furans by Regioselective Palladium(0)-Catalyzed Coupling Reactions: Application to the Syntheses of Rosefuran and the F5 Furan Fatty Acid

“…Equation (f)] to undergo a facile methyldebroAs an example for a 2,3,5-trisubstituted furan we had selected a furan fatty acid, namely the so-called F 5 acid (26) mination with MeZnCl in the presence of PdCl 2 (PPh 3 ) 2 . In contrast, under the same reaction conditions furan 20 gave that had been previously prepared by Schlenk et al from methyl 3-methylfuran-2-carboxylate in 5 steps (3% yield) [31] a mixture of starting material 20, hydrodebrominated product, and the desired methyldebrominated product 21 in a and by Marson et al from cyclodecanone in 6 steps (13% yield). [2b] We started the synthesis (Scheme 3) from the 39:21:40 ratio (GLC).…”