3810-34-2Relevant academic research and scientific papers
Synthesis of 4,8-Bis(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclooctan-2-ones and Determination of their Relative Configuration via Long-range
Quideau, Stephane,Ralph, John
, p. 653 - 660 (2007/10/02)
A short synthesis of the furofuranoid lignan, 4-cis,8-cis-bis(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclooctan-2-one (MEL), was accomplished via a simple regioselective hydride reduction of the dilactone parent octane-2,6-dione>, followed by deoxygenation of the lactone-lactol intermediate via silane hydride transfer.The 4-trans-8-cis(iso-MEL) and the 4-cis-8-trans(epi-MEL) isomers, and a fourth related compound, featuring a 3-fused 5-membered ring skeleton were additionally formed.All four compounds were fully characterized by use of 1D and 2D NMR techniques.Examination of the long-range coupled proton network by delayed COSY experiments allowed determination of the relative configuration of these 4,8-diaryl-3,7-dioxabicyclooctan-2-one structures.The pathways followed by these long-range proton couplings and implications of the long-range and vicinal couplings with respect to favoured conformations are discussed.
A New Synthetic Route to Furofuranoid Lignans via Intramolecular Mukaiyama reaction
Stevens, David R.,Till, Clive P.,Whiting, Donald A.
, p. 185 - 190 (2007/10/02)
The sequence set out in Scheme 1 provides a short and expedient synthesis of a number of (+/-)-furofuranoid lignans, including styraxin 3 (antitumor), aptosimon 5, asarinin 6, pluviatilol 7, 'MEL' 4 (inhibitor of germination) and related compounds.
Lignin-Feruloyl Ester Cross-links in Grasses. Part 2. Model Compound Syntheses
Ralph, John,Helm, Richard F.,Quideau, Stephane
, p. 2971 - 2980 (2007/10/02)
Five compounds which model the various structures produced when feruloyl esters are copolymerized into lignins have been synthesized.These models represent the lignin-feruloyl-polysaccharide structures which have been theorized to exist in the Graminaceae but have yet to be isolated.Complete spectroscopic characterization provides important chemical-shift information to facilitate the identification of these linkages in native lignins and synthetic DHP polymers.Methyl 5-O-feruloyl>-α-L-arabinofuranoside, a model for the α-linkage of feruloyl esters to lignin, was prepared as a mixture of threo and erythro isomers by addition of methyl 5-O-(E)-feruloyl-α-L-arabinofuranoside (FA-Ara) to the quinone methide derived from 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (guaiacylglycerol-β-guaiacyl ether).Methyl 5-O-feruloyl>-α-L-arabinofuranoside, a β-aryl ether model, was prepared by a method analogous to one used for the synthesis of guaiacylglycerol-β-guaiacyl ether; FA-Ara was added to 4-acetoxy-β-bromo-3-methoxyacetophenone, and the product was hydroxymethylated and reduced.The peracetate of methyl 5-O--α-L-arabinofuranoside, a compound which models the attack of lignin radicals on the β-position of the feruloyl ester, was prepared by elimination of the β-proton from the quinone methide derived from ethyl 3-hydroxy-3-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propanoate.As in the preparation of synthetic copolymers between coniferyl alcohol andFA-Ara, only a single geometrical isomer was produced.Synthesis of both isomers of derived compounds and detailed NMR analysis indicated that this was the expected Z-isomer.A model for β-5 coupled products, 3-acrylic acid bis(methyl 5-deoxy-α-L-arabinofuranosid-5-yl) ester, was obtained as a cis/trans mixture in 55percent yield by radical coupling of FA-Ara using silver(I) oxide.Finally, the crossed β-β-compound 4,8-exo-bis(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclooctan-2-one (MEL) was obtained, in admixture with its isomer iso-MEL, pinoresinol, and the dilactone 4,8-exo-bis-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclooctan-2,6-dione, from mixed radical coupling of coniferyl alcohol and ferulic acid via silver(I) oxide.
Synthesis and 1H N.M.R. Spectroscopic Analysis of Some 3,7-Dioxabicyclooctane Lignans
Velde, Vincent Vande,Lavie, David,Gottlieb, Hugo E.,Perold, Guido W.,Scheinmann, Feodor
, p. 1159 - 1164 (2007/10/02)
Within the framework of a synthetic project towards the preparation of the natural germination inhibitor 2,6-diaryl-3,7-dioxabicyclooctane, several molecules with the same bicyclic skeleton were prepared and their 1H n.m.r. spectra are described in detail.For the symmetrical systems particularly, the spectra exhibited second-order features and were interpreted analytically or, when necessary, by computer simulation.These n.m.r. data enabled a conformational analysis of the ring system.
