Furyl Alcohol Research Articles

Kinetics of biodegradation of strengthening polymer systems based on copolymers of lactic acid and biogenic activators

The production of bioplastics based on copolymers of maleic anhydride with the addition of lactic acid and furyl alcohol is described. The obtained copolymers are promising for use as reinforcing polymer systems of cellulose-containing materials used in packaging. It has been shown that the use of lactic acid and furyl alcohol makes it possible to obtain synthetic bioplastics that are rapidly degradable in natural conditions, which is favorable for environmental protection.

Synthetic Efforts and Ultimate Limitation to an Asymmetric Achmatowicz Approach Toward EBC-23.

An effort toward the total synthesis of the polyketide natural product EBC-23 is reported. The asymmetric approach is convergent and uses a late-stage Claisen-like enolate/acid chloride coupling to establish a key 1,3-diketone intermediate. The 1,3-diketone target is an oxidized form of the hydrated natural product, which fails to spiroketalize. The convergent asymmetric synthesis uses an asymmetric Noyori transfer hydrogenation of a β-furyl ketoester to enantioselectively form a chiral furyl alcohol. An Achmatowicz/Jones/Luche three-step reaction sequence was used to stereoselectively convert the furyl alcohol into the 5-hydroxy-pyran-2-one. The absolute stereochemistry of the 1,3-polyol fragment was established by a Leighton allylation. A subsequent Grubbs cross-metathesis, and Evans acetalation were used to install the 1,3-syn-diol stereochemistry.

De Novo Asymmetric Approach to Aspergillide‐C: Synthesis of 4‐epi‐seco‐Aspergillide‐C

AbstractAn asymmetric approach toward the synthesis of the marine natural product aspergillide‐C has been developed. The convergent asymmetric synthesis uses two asymmetric Noyori transfer hydrogenations to enantioselectively prepare the two key fragments, aC‐1 toC‐7 pyranone fragment and aC‐8 toC‐14β‐keto‐sulfone fragment. The absolute stereochemistry of the pyranone fragment was established by a Noyori reduction ofβ‐furylketoester to form a furyl alcohol. An Achmatowicz rearrangement was used to stereoselectively convert the furyl alcohol in to the key pyranone fragment. The absolute stereochemistry of theβ‐keto‐sulfone fragment was established by a Noyori reduction of an ynone to form a propargyl alcohol. An alkyne zipper isomerization was used to stereospecifically convert the propargyl alcohol in to theβ‐keto‐sulfone fragment. Finally, a Pd‐catalyzedC‐glycosylation was used to diastereoselectively couple the two fragments, which when combined with a reduction and Julia‐Kocienski type elimination formed a protected variant of the 4‐epi‐seco‐acid of aspergillide‐C.

Inhibitory activity of Co-microencapsulation of cell free supernatant from Lactobacillus plantarum with propolis extracts towards fish spoilage bacteria

Antibacterial properties of microencapsulated Lactobacillus plantarum cell-free supernatant (CFS) in combinations with aqueous or ethanolic propolis extract at doses of 1% against fish spoilage bacteria were investigated. Microencapsulated samples contained more than 17 compounds, of which furyl alcohol, acetic acid, maltol, and 2(5H) furanon were identified as common compounds. The effects of microencapsulated CFS from L. plantarum in combination with or without propolis extracts on the fish spoilage bacteria varied according to the bacterial species. Among the fish spoilage bacteria, the highest antimicrobial activity of samples was observed against P. damselae with >15.5 mm inhibition diameter zone. Pure and microencapsulated CFS from L. plantarum showed the lowest antimicrobial effects on P. mirabilis with a corresponding inhibition diameter zone of 8.33 and 8.00 mm. Microencapsulated CFS from L. plantarum in combination with aqueous propolis extract had 25 mg/ml of MIC and 50 mg/ml of MBC on all bacteria although the bactericidal effect of microencapsulated samples in combination with ethanolic propolis extract occurred at a level of above 50 mg/ml. The study results revealed that co-microencapsulation of CFS obtained from L. plantarum with propolis extract, especially its aqueous extract, could be potentially used as antimicrobial agents to overcome microbial growth in foods.

Selective and Efficient Production of Biomass-Derived Vinylfurans

We describe a two-step catalytic process for the selective and rapid conversion of biomass-derived acetylfurans into vinylfurans. This is accomplished by nearly quantitatively reducing acetylfurans into furyl alcohols using a copper chromite catalyst and exploiting the promoter-like properties of ethanol, the solvent. Subsequently, furyl alcohol is dehydrated using solid-acid catalysts. Catalyst deactivation due to oligomeric species is a major issue, but the activity can be partially recovered by calcination. Optimization of reaction conditions showed that the selectivity could be increased by using nitrobenzene, a polar aprotic solvent. The high-boiling point solvent allows the formation of vinylfurans with a selectivity of up to 85%; the product can be isolated in high purity by distillation.

Corrosion resistance of steel reinforcement in polymer silicate shyngizite concrete

Polymersilicate concrete is used for structures of industrial buildings in many industries, where production processes form an acidic wet- gas operating environment. The lightweight polymer silicate shungizite concrete, proposed by the author for external walls, can also be attributed to these materials. The polymersilicate composition is based on the components of schungite and schungizite. The composition also included liquid glass, sodium silicofluoride and furyl alcohol. These ingredients are usually adopted for polymersilicate concrete. Previously, the author carried out the research of physical and mechanical properties of the composition. The components based on schungite and schungizite were chosen because of their high acid resistance. The issue of the corrosion resistance of reinforcement in light polymer-silicate concrete has not been studied enough. This article presents the results of investigations of the corrosion resistance of steel reinforcement in polymer silicate shungizit concrete. The investigations were carried out in an airy environment of high humidity and in solutions of sulfuric acid of various concentrations. After the established time limits for corrosion testing, the corrosion of reinforcement in samples was not observed. Such a result was obtained due to the dense structure of the material and high acid resistance of the constituent components on the basis of schungite and shungizite. There is no need for additional protection of the concrete surface to prevent corrosion of the reinforcement in it . The author recommends the use of the material for reinforced structures of external walls exposed to an acidic wet- gas operating environment.

Polyacrylate crosslinked with furyl alcohol grafting bismaleimide: A self-healing polymer coating

Leather surface is easily scratched and then discarded somewhere, which might result in a great waste of resources and economics. Self-healing materials could efficiently solve this problem. In this study, furfuryl alcohol (FA) and bismaleimide (BMI) were introduced to polyacylate for preparing self-healing polyacrylate emulsion (PA/(FA-BMI)), which was used as a finishing agent in leather process. Fourier transform infrared spectroscopy indicated that Diels-Alder reaction had taken place between FA and BMI. The dynamic light scattering, transmission electron microscopy and scanning electron microscopy results showed that FA and BMI were dispersed uniformly in polyacrylate. Thermogravimetric analysis results indicated that the addition of FA and BMI increased the thermal stability of polyacrylate. The ultra depth of field microscope (UDFM) results showed that the damaged PA/(FA-BMI) could be self-healing completely when the amount of FA and BMI was 5 %. The leather after finishing with PA/(FA-BMI) could be fully self-healing in 5 h at 50 °C. PA/(FA-BMI) endowed the finished leather good self-healing performance towards scratches on the surfaces. Meanwhile, physical and mechanical properties of the leather finished by PA/(FA-BMI), such as tensile strength, tear strength, wet and dry rub resistance, were also improved obviously.

Asymmetric synthesis of 7-aza-phomopsolide E and its C-4 epimer

A flexible, enantioselective route to highly functionalized α,β-unsaturated δ-lactones has been applied to the synthesis of 7-aza-phomopsolide E and its C-4 epimer. This approach relies on the application of the Noyori asymmetric hydrogenation of furyl ketone to produce the secondary furyl alcohol in high enantioexcess, which can be stereoselectively transformed into α,β-unsaturated-δ-lactones by a short, highly diastereoselective oxidation and reduction sequence. DCC and acid chloride couplings were used to introduce the side chains of the two natural product analogues.

Indium(III) triflate promoted synthesis of alkyl levulinates from furyl alcohols and furyl aldehydes

A facile protocol for the alcoholysis of furfuryl alcohol into levulinate esters has been developed employing low catalyst loadings of indium(III) triflate. This method provides a rapid and efficient route for the synthesis of these useful materials. The alcoholysis reactions of 5-hydroxymethylfurfural (HMF), furfural and furfural dimethylacetal were also investigated under these reaction conditions.

A New Concise Synthesis of (+)-Ipomeamarone, (−)-Ngaione, and Their Stereoisomers

Abstract A new concise and enantiocontrolled total synthesis of (+)-ipomeamarone (1), a well-known phytoalexin, is described. The key step involved a tetrahydrofuran ring construction from optically active furyl alcohol 5 via the π-allyl palladium complex with a chiral phosphine ligand. This procedure was also applicable to the synthesis of (−)-ngaione (2) and its stereoisomers.

ChemInform Abstract: Ferrous Methanesulfonate as an Efficient and Recyclable Catalyst for the Tetrahydropyranylation of Alcohols and Phenols under Solvent‐Free Conditions.

AbstractFerrous methanesulfonate catalyzes tetrahydropyranylation of benzylic, primary, secondary, tertiary, cyclic, allyl, and furyl alcohols as well as phenols under solvent‐free conditions.

MS463 TYPE 2 DIABETES-ASSOCIATED ATHEROTHROMBOSIS: INSIGHTS INTO PATHOGENESIS AND THERAPEUTIC TARGET

A flexible, enantioselective route to highly functionalized α,β-unsaturated δ-lactones has been applied to the synthesis of 7-oxa-phomopsolide E and its C-4 epimer. This approach relies on the application of the Noyori asymmetric hydrogenation of furyl ketone to produce the secondary furyl alcohol in high enantioexcess, which can be stereoselectively transformed into α,β-unsaturated-δ-lactones by a short, highly diastereoselective oxidation and reduction sequence. DCC and Mitsunobu coupling were used to introduce the side chains of the two natural product analogs.

Enantioselective Addition of 2-Furylaluminum to Ketones

The development of a new asymmetric 2-furyl addition of (2-furyl)aluminum to ketones is reported. The corresponding chiral tertiary furyl alcohols are versatile intermediates in organic synthesis and they are obtained in good to excellent yields.

Addition/Oxidative Rearrangement of 3-Furfurals and 3-Furyl Imines: New Approaches to Substituted Furans and Pyrroles

Furans and pyrroles are important synthons in chemical synthesis and are commonly found in natural products, pharmaceutical agents, and materials. Introduced herein are three methods to prepare 2-substituted 3-furfurals starting from 3-furfural, 3-bromofuran, and 3-vinylfurans. Addition of a variety of organolithium, Grignard, and organozinc reagents (M-R) to 3-furfural provides 3-furyl alcohols in high yields. Treatment of these intermediates with NBS initiates a novel oxidative rearrangement that results in the installation of the R group in the 2 position of the 2-substituted 3-furfurals. Likewise, metalation of 3-bromofuran with n-BuLi and addition to benzaldehyde provides a furyl alcohol that is converted to 2-phenyl 3-furfural upon oxidative rearrangement. Enantioenriched disubstituted furans can be prepared starting with the Sharpless asymmetric dihydroxylation of 3-vinylfurans. The resulting enantioenriched diols undergo the oxidative rearrangement to furnish enantioenriched 2-substituted 3-furfurals with excellent transfer of asymmetry. This later method has been applied to the enantioselective preparation of an intermediate in Honda's synthesis of the natural product (-)-canadensolide. Mechanistic studies involving deuterium-labeled furyl alcohol suggest that the oxidative rearrangement proceeds through an unsaturated 1,4-dialdehyde intermediate. The alcohol then cyclizes onto an aldehyde, resulting in the elimination of water and rearomatization. On the basis of this proposed mechanism, we found that 3-furyl imines undergo the addition of organometallic reagents to provide furyl sulfonamides. Under the oxidative rearrangement conditions, 2-substituted 3-formyl pyrroles are formed, providing a novel route to these heterocycles. In contrast to the metalation of heterocycles, which often lead to mixtures of regioisomeric products, these new oxidative rearrangements of furyl alcohols and furyl sulfonamides generate only one regioisomer in each case.

Chiral tertiary 2-furyl alcohols: diversified key intermediates to bioactive compounds. Their enantioselective synthesis via (2-furyl)aluminium addition to ketones catalyzed by a titanium catalyst of (S)-BINOL

Novel asymmetric 2-furyl additions of (2-furyl)AlEt(2)(THF) to aromatic ketones and one alpha,beta-unsaturated ketone catalyzed by a titanium catalyst of 10-20 mol% (S)-BINOL are reported to furnish tertiary furyl alcohols in good to excellent enantioselectivities of 87-93% ee.

Total Syntheses of Ipomoeassin B and E

A concise, flexible, and efficient total synthesis of the cytotoxic resin glycosides ipomoeassin B (1) and ipomoeassin E (2) is reported which features the advantages of a novel protecting group strategy employing (Z)-3-dimethyl(phenyl)silyl-2-propenoic acid as cinnamic acid surrogate. The use of this readily available compound allowed the macrocycle of the glycolipids to be formed by ring closing olefin metathesis (RCM) with the aid of the second generation Grubbs carbene complex 12. The resulting E/Z mixture could be selectively hydrogenated using Wilkinson's catalyst [RhCl(PPh3)3] without affecting the unsaturated esters in the periphery of the compound, before the C-silyl group was cleaved off with TASF [tris(dimethylamino)sulfonium difluorotrimethylsilicate] under notably mild conditions to release the required cinnamate moiety. Other key steps of the synthesis route comprise the formation of the disaccharide linkage by the trichloroacetimidate method, the formation of the chiral acid segment 19 via a VO(acac)2-catalyzed, tert-BuOOH-induced oxidative rearrangement of the optically pure furyl alcohol (−)-15 (Achmatowicz-type reaction), and a reductive cleavage of the 4,6-O-p-methoxybenzylidene acetal in 5 with NaBH3CN and Me3SiCl (TMSCl), the regiochemical course of which was found to be opposite to that previously reported in the literature for sterically less encumbered substrates.

Gold Catalysis: Dihydroisobenzofurans and Isochromanes by the Intramolecular Furan/Alkyne Reaction

AbstractA series of furyl alcohols and homofuryl alcohols was synthesized by reduction of furfurals or reaction of furyllithium compounds with epoxides and subsequent propargylation. The gold‐catalyzed cycloisomerization of these products furnished dihydroisobenzofurans and isochromanes. Crystal structure analyses proved the sequence of the substituents for both classes of products. Unsaturated dicarbonyl compounds as side‐products show the mechanistic relationship to the analogous platinum‐catalyzed reactions. Neither ester groups, even on the 4‐position of the furan ring, nor aryl bromides hinder the catalysis by gold. In the case of a substrate with an allyl ether in the side chain, a side‐product, which provides evidence for a reaction of the alkyne with an inverse regioselectivity, was observed.

Studies Towards the Synthesis of Salvinorin A

Salvinorin A 1, a psychoactive neoclerodane diterpenoid from the Mexican sage S. divinorum, has gained interest as a selective κ-opioid receptor agonist. Non-racemic 3-furylamines 9a and 9b have been prepared from (+)-pseudoephedrine and (–)-ephedrine for application in the stereoselective synthesis of the ketone ring of 1. Diels–Alder reaction of 9b with methyl acrylate in aqueous media, followed by selective ether bridge cleavage, has allowed access to the cyclohexenone 17 with preservation of stereochemistry at C2. A model route to the lactone ring has also been achieved through a one-pot deconjugation/esterification procedure of 2-bromocrotonyl chloride 20 to the furyl alcohol 19 followed by Reformatski-mediated ring closure.

Microstructure and phase behavior of concentrated silica particle suspensions

Dispersion stability and microstructural transition of colloidal silica suspensions were examined by rhe- ological measurements under either steady simple shear or os cillatory flow. Monodisperse silica particles were prepared by the so-called modified Stober method and were stabilized by either steric or electrostatic repulsive force. Depending upon the methods of stabilization, the suspension showed hard-sphere or soft-sphere response. In particular, silica suspensions exhibited hard-sphere response when the silica spheres coated with 3-(trimethoxysilyl)propyl methacry - late (MPTS; (CH3O)3Si(CH2)3OCOC(CH3)=CH2) were dispersed in a refractive-index matching solvent, tetrahydrofur- furyl alcohol. On the other hand, silica particles in aqueous media behaved like soft spheres with long-range elec- trostatic repulsive interactions when th ey were coated with steric layer of aminosilane coupling agent, N-(3-(trimethox - ysilyl)propyl)ethylenediamine ((CH3O)3Si(CH2)3NHCH2CH2NH2). In this case, the electrostatic repulsion or equiva- lently the softness of the silica spheres was controlled by th e ionic strength using a symmetric salt KCl. Both the hard- sphere and soft-sphere suspensions showed stable shear-th inning behavior without experiencing shear-induced floccula- tion. Moreover, the oscillatory shear rheology showed that the electrostatically stabilized soft-sphere suspensions underwent a microstructural transition from liquid-like to solid-li ke structure when either the particle loading increased or the ionic strength was reduced.

Synthesis of 7-oxa-phomopsolide E and its C-4 epimer

A flexible, enantioselective route to highly functionalized α,β-unsaturated δ-lactones has been applied to the synthesis of 7-oxa-phomopsolide E and its C-4 epimer. This approach relies on the application of the Noyori asymmetric hydrogenation of furyl ketone to produce the secondary furyl alcohol in high enantioexcess, which can be stereoselectively transformed into α,β-unsaturated-δ-lactones by a short, highly diastereoselective oxidation and reduction sequence. DCC and Mitsunobu coupling were used to introduce the side chains of the two natural product analogs.