fumarates has been researched along with 2-3-bis(3--hydroxybenzyl)butyrolactone* in 1 studies
1 other study(ies) available for fumarates and 2-3-bis(3--hydroxybenzyl)butyrolactone
| Article | Year |
|---|---|
Free-radical-mediated conjugate additions. Enantioselective synthesis of butyrolactone natural products: (-)-enterolactone, (-)-arctigenin, (-)-isoarctigenin, (-)-nephrosteranic acid, and (-)-roccellaric acid.
Lewis acid-mediated conjugate addition of alkyl radicals to a differentially protected fumarate 10 produced the monoalkylated succinates with high chemical efficiency and excellent stereoselectivity. A subsequent alkylation or an aldol reaction furnished the disubstituted succinates with syn configuration. The chiral auxiliary, 4-diphenylmethyl-2-oxazolidinone, controlled the stereoselectivity in both steps. Manipulation of the disubstituted succinates obtained by alkylation furnished the natural products (-)-enterolactone, (-)-arctigenin, and (-)-isoarctigenin. The overall yields for the target natural products were 20-26% over six steps. Selective functionalization of the disubstituted succinates obtained by aldol condensation gave the paraconic acid natural products (-)-nephrosteranic acid (8) and (-)-roccellaric acid (9). The overall yield of the natural products 8 and 9 over four steps was 53% and 42%, respectively. Topics: 4-Butyrolactone; Alkylation; Biological Products; Catalysis; Chemistry, Organic; Free Radicals; Fumarates; Furans; Lactones; Lignans; Magnetic Resonance Spectroscopy; Molecular Structure; Stereoisomerism; Succinates | 2002 |