Ether Epoxide Research Articles

Side chains affect the melt processing and stretchability of arabinoxylan biomass-based thermoplastic films

Hydrophobization of hemicellulose causes melt processing and makes them stretchable thermoplastics. Understanding how native and/or appended side chains in various hemicelluloses after chemical modification affect melt processing and material properties can help in the development of products for film packaging and substrates for stretchable electronics applications. Herein, we describe a one-step and two-step strategy for the fabrication of flexible and stretchable thermoplastics prepared by compression molding of two structurally different arabinoxylans (AX). For one-step synthesis, the n-butyl glycidyl ether epoxide ring was opened to the hydroxyl group, resulting in the introduction of alkoxide side chains. The first step in the two-step synthesis was periodate oxidation. Because the melt processability for AXs having low arabinose to xylose ratio (araf/xylp<0.5) have been limited, two structurally distinct AXs extracted from wheat bran (AXWB, araf/xylp = 3/4) and barley husk (AXBH, araf/xylp = 1/4) were used to investigate the effect of araf/xylp and hydrophobization on the melt processability and properties of the final material. Melt compression processability was achieved in AXBH derived samples. DSC and DMA confirmed that the thermoplastics derived from AXWB and AXBH had dual and single glass transition (Tg) characteristics, respectively, but the thermoplastics derived from AXBH had lower stretchability (maximum 160%) compared to the AXWB samples (maximum 300%). Higher araf/xylp values, and thus longer alkoxide side chains in AXWB-derived thermoplastics, explain the stretchability differences.

Bioinspired-Metalloporphyrin Magnetic Nanocomposite as a Reusable Catalyst for Synthesis of Diastereomeric (-)-Isopulegol Epoxide: Anticancer Activity Against Human Osteosarcoma Cells (MG-63).

In the present study, we developed a green epoxidation approach for the synthesis of the diastereomers of (−)-isopulegol benzyl ether epoxide using molecular oxygen as the oxidant and a hybrid manganese(III)-porphyrin magnetic reusable nanocomposite as the catalyst. High activity, selectivity, and stability were obtained, with up to four recycling cycles without the loss of activity and selectivity for epoxide. The anticancer effect of the newly synthesized isopulegol epoxide diastereomers was evaluated on a human osteosarcoma cell line (MG-63); both diastereomers showed similar in vitro potency. The measured IC50 values were significantly lower than those reported for other monoterpene analogues, rendering these epoxide isomers as promising anti-tumor agents against low prognosis osteosarcoma.

Network from Dihydrocoumarin via Solvent-Free Metal-Mediated Pathway: A Potential Structure for Substantial Toughness Improvement of Epoxidized Plant Oil Materials

The main challenge in converting polymerized epoxidized plant oils (P-EPO) to high performance materials is the limitation of their short cross-link structures and brittle properties. Herein, a network (N-2) fabricated from a renewable material, dihydrocoumarin (DHC), demonstrated the potential to overcome substantially the brittleness of P-EPO material. The fused ring in DHC was successfully opened via a solvent-free chromium(III) salen-mediated pathway, and a novel network, termed N-2, was created through an alternating copolymerization of DHC and diglycidyl ether epoxides. Repeating ether units in N-2 offered the capacity to sustain large deformation, and phenoxide end groups provided the reactivity to attack epoxides. Once a double network was built between N-2 and EPO derived network (N-1), a substantial performance improvement of P-EPO could be achieved. We targeted epoxidized soybean oil (ESO) as the model material, which showed a significant toughness enhancement (9-fold improvement in elongation ...

Synthesis of glycidyl ethers derived from terpene α-amino oximes and β-substituted alcohols on their basis

3-Carene, α-pinene, and limonene α-(dimethylamino)oximes were converted to glycidyl ethers at the oxime hydroxyl. The compounds obtained were involved in the reactions with amines, imidazole, as well as with anions of these dimethylamino oximes. The glycidyl ether epoxide ring opening by amines under microwave irradiation conditions proceeds considerably faster than upon convection heating.

New insights into radical and cationic polymerizations upon visible light exposure: role of novel photoinitiator systems based on the pyrene chromophore

New aromatic derivatives PyD based on a pyrene moiety are proposed here as new photoinitiators (PIs) in multi-component systems (with an iodonium salt, a sulfonium salt and optionally a silane) for the radical polymerization of acrylates and the cationic polymerization of epoxy, epoxy-silicone and vinyl ethers. These new photoinitiators allow the use of a long wavelength excitation (using visible light delivered by a halogen lamp, a laser diode at 457 nm or a Xe–Hg lamp). Excellent polymerization profiles are obtained. For polymerization processes using pyrene, very low conversions are reached in agreement with the lack of absorption of this compound for λ > 380 nm i.e.PyDs are attractive compounds for visible light. Acrylate–epoxide, acrylate–vinyl ether and vinyl ether–epoxide blends are also easily polymerized i.e. for the synthesis of interpenetrating or crosslinked polymer networks. The initiation step mechanisms analyzed by ESR, fluorescence, steady state photolysis and laser flash photolysis experiments are discussed.

Effects of various elicitors on the accumulation and secretion of spiroketal enol ether diacetylenes in feverfew hairy root culture

In a hairy root culture of &lt;em&gt;Tanacetum parthenium&lt;/em&gt; treated with yeast extract (YE), silver nitrate (AgNO&lt;sub&gt;3&lt;/sub&gt;) and microalgal glycoproteins (MGPS), contents of four spiroketal enol ether type diacetylenes were mesured. The elicitors transiently reduced contents of three constitutive spiroketal enol ethers and selectively enhanced accumulation of cis-C13-spiroketal enol ether epoxide ((E)-3,4-epoxy-2-(2,4-hexadiynylidene)-1,6-dioxaspiro[4.4]nonane) in the roots. The most abundant formation of cis-C13-spiroketal enol ether epoxide was observed after 48-96 h of AgNO&lt;sub&gt;3&lt;/sub&gt; treatment and 96 h of YE treatment (over 3-fold increase compared with the control). The applied elicitors caused enhanced liberation of cis-C13-spiroketal enol ether epoxide to the culture medium. The results show that diacetylene accumulation pattern in the elicited hairy roots is affected in a similar manner, irrespectively of the elicitor applied.

Molecular Dynamics Simulations of Comb-Branched Poly(epoxide ether)-Based Polymer Electrolytes

Molecular dynamics (MD) simulations using many-body polarizable force field were performed on comb-branched poly(epoxide ether) (PEPE) polymer electrolytes doped with lithium bistrifluoromethanesulfonamide (LiTFSI) salt as a function of temperatures from 333 to 423 K at ether oxygen (EO) to lithium ratio of 20. MD simulations predicted electrolyte conductivity in good agreement with experiments. The fraction of solvent-separated ions and lithium cation environment for PEPE/LiTFSI were similar to those found for the linear poly(ethylene oxide) (PEO)/LiTFSI electrolyte. The Li+ cations had the highest probability to be coordinated by EOs near the PEPE polymer backbone and the lowest probability being coordinated by EO's at the end of side chains. Segmental dynamics of the backbone was slower by 2 orders of magnitude compared to the dynamics of side-chain ends. The Li+ self-diffusion coefficient was approximately an order of magnitude lower than the TFSI- anion self-diffusion coefficient. Visualization of the lithium motion revealed that the most mobile Li+ cations moved by hopping from a side chain to another without being complexed by the backbone. The influence of the backbone−Li+ interactions and the backbone stiffness on ion transport was investigated in MD simulations performed on the PEPE/LiTFSI-like electrolytes with the same PEPE architecture but a very stiff backbone that does not complex lithium cations. The ion transport in these model electrolytes was compared to that of the original PEPE/LiTFSI electrolyte.

Salicylate and methyl jasmonate differentially influence diacetylene accumulation pattern in transformed roots of feverfew

In hairy root cultures of feverfew ( Tanacetum parthenium (L.) Sch. Bip.), treated with methyl jasmonate (MJ), accumulation of spiroketal enol ether type diacetylenes of known deterrent activity was increased about two-fold. The phenomenon was independent of the root clone studied. The maximum total acetylene content (≈2.5 and 1.1% dry weight in clones M2 and I2, respectively) was observed after 72–96 h MJ treatment. Salicylic acid (SA) transiently reduced a content of constitutive spiroketal enol ethers, common for all root clones, but selectively enhanced accumulation of cis-C 13-spiroketal enol ether epoxide (( E)-3,4-epoxy-2-(2,4-hexadiynylidene)-1,6-dioxaspiro[4.4]nonane) ( 2), present in clone M2. Simultaneous addition of SA and MJ to the culture medium influenced diacetylene spectrum in a salicylate-like manner, but accumulation of the epoxide in clone M2 was more abundant (up to 6-fold increase compared with the control).

A General Approach to L-(+)-Furanomycin and Some Stereoisomers and Analogues Using Furoisoxazoline Intermediates Syntheses via Isoxazolines, Part 24. Part of the planned dissertation of P. J. Zimmermann. We thank the Volkswagen-Stiftung, Hannover, the Fonds der Chemischen Industrie, the Landesgraduiertenförderung Baden-Württemberg (doctoral fellowship to P.J.Z.), and Bayer AG, Wuppertal, for financial support of this work. I.B. gratefully acknowledges a grant from

An unexpectedly stable, isolable enol ether epoxide is the key intermediate in a new, efficient synthesis of the antibiotic L-(+)-furanomycin (3; a natural α-amino acid) and a group of analogues. The furo[2,3-d]isoxazoline 1 and its diastereomer result from cycloaddition of methylfuran to a glyceronitrile oxide, serving as a chiral glycine equivalent; epoxidation of 1 then affords the stable enol ether epoxide 2. Concise subsequent reactions of 1 and 2 lead to 3, its 5-epimer, and structural analogues of 3.

A diacetylenic spiroketal enol ether epoxide, AL-1, from Artemisia lactiflora inhibits 12- O-tetradecanoylphorbol-13-acetate-induced tumor promotion possibly by suppression of oxidative stress

The inhibitory effects of the diacetylenic spiroketal enol ether epoxide AL-1 from Artemisia lactiflora on a variety of tumor promoter-induced biological responses such as oxidative stress as well as tumor promotion in ICR mouse skin were investigated. AL-1 inhibited TPA-induced intracellular peroxide formation in differentiated HL-60 cells, suggesting that this suppression might be attributable to the inhibition of O 2 − generation. In a double TPA application system in mouse skin, double pretreatments of AL-1 (810 nmol) significantly suppressed double TPA application-induced H 2O 2 generation. Pretreatment of AL-1 only before the second TPA treatment was sufficient to inhibit, while only with first treatment was not. From these results we concluded that AL-1 is a specific inhibitor of the activation phase in H 2O 2 production induced by double TPA treatments. In addition, AL-1 strongly inhibited tumor promoter-induced Epstein–Barr virus (EBV) activation in Raji cells (IC 50=0.5 μM), which was comparable to or even stronger than that of curcumin, a well-known antioxidative chemopreventer from turmeric. In a two-stage carcinogenesis experiment with TPA (topical application at 1.6 nmol) and 7,12-dimethylbenz[a]anthracene (DMBA, at 0.19 μmol) in ICR mouse skin, topical application of AL-1 (at 160 nmol) significantly reduced tumor incidence, the numbers of tumors per mouse, and edema formation by 58% ( P<0.01 in t-test), 20% ( P<0.005 in χ 2-test) and 42% ( P<0.01), respectively. These results together indicate that an inhibitor of O 2 − generation is an effective chemopreventer of mouse skin carcinogenesis by their antioxidative property.

Synthesis and cationic photopolymerization of monomers based on nopol

Starting with nopol [(R)-(−)-2-(2′-hydroxyethyl)-6,6-dimethyl-8-oxatricyclo[3.1.1.12,3]octane, I] as a substrate, two new, interesting monomers, allyl nopol ether epoxide III and nopol 1-propenyl ether epoxide IV, were prepared. The photoinitiated cationic polymerizations of these two monomers as well as several other model compounds were studied using real-time infrared spectroscopy. Surprisingly, the rates of epoxide ring-opening polymerization of both monomers were enhanced as compared to those of the model compounds. Two different mechanisms which involve the free radical induced decomposition of the diaryliodonium salt photoinitiator were proposed to explain the rate acceleration effects. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1199–1209, 1999

Free Radical Induced Acceleration of Cationic Photopolymerization

Two new monomers based on α-terpineol were prepared, allyl α−terpineol ether epoxide (III) and 1-propenyl ether α-terpineol epoxide (IV). The photoinitiated cationic polymerizations of these two monomers as well as two model compounds, 1-propenyl α-terpineol ether and methyl α-terpineol ether epoxide, were studied using real-time infrared spectroscopy. Surprisingly, the rates of epoxide ring-opening polymerization of both monomers were greatly enhanced as compared to the model compounds. At the same time, the rate of polymerization of the 1-propenyl ether groups in IV was depressed. Two different mechanisms which involve the free radical induced decomposition of the diaryliodonium salt photoinitiator were proposed to explain the rate acceleration effects.

ChemInform Abstract: Formation of Enol Ether Epoxides by Reaction of (9S,10E,12Z)‐ Hydroperoxyoctadecadienoic Acid with Plasmalogens.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Bildung von Enolether‐Epoxiden durch Einwirkung von (9S,10E,12Z)‐Hydroperoxyoctadecadiensäure auf Plasmalogene

Formation of Enol Ether Epoxides by Reaction of (9S,10E,12Z)‐Hydroperoxyoctadecadienoic Acid with Plasmalogens(9S,10E,12Z)‐Hydroperoxyoctadecadienoic acid (8a) oxidizes enol ethers (e.g. 2 and neutral plasmalogens 3) under physiological conditions (pH = 6.6, room temperature). The reaction products, unstable enol ether epoxides 9a and 10a, react as recently demonstrated with methanol to α‐hydroxyaldehyde dialkyl acetals 11a or with 1,2‐ethanedithiol to 2‐(α‐hydroxyalkyl)dithiolans 13a which can be detected by GC/MS after trimethylsilylation. If [18O2]‐(9S,10E,12Z)‐hydroperoxy‐octadecadienoic acid (8b) is used instead of 8a one atom of 18O is incorporated into the enol ether epoxide and found in the α‐hydroxy group of the aldehyde derivatives 11 and 13.

ChemInform Abstract: Enol Ether Epoxides and Products Resulting from Their Reaction with Nucleophiles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Enoletherepoxide und ihre Reaktionsprodukte mit Nucleophilen

Enol Ether Epoxides and Products Resulting from Their Reaction with Nucleophiles1,2‐Epoxydecyl pentyl ether (9a) was synthesized by treatment of 1‐decenyl pentyl ether (5) with diemthyldioxirane (8). The enol ether epoxide 9a, characterized by its mass, 1H‐ and 13C‐NMR spectra, reacts readily with hydride, O‐, S‐ and N‐nucleophiles. Similar reactions are expected to take place in the organism after biological oxidation of plasmalogens to their epoxides. This hypothesis is verified by detection of mixed acetals after tissue workup.

Preparation and Characterization of New C-11 Oxygenated Artemisinin Derivatives

Anhydrodihydroartemisinin [2], a potent antimalarial sesquiterpene endoperoxide, was converted to 11-hydroxyartemisinin [4], 11-hydroxy-11-epi-artemisinin [5], a ketone derivative 7 of artemisinin, and an enol ether epoxide 8. Compounds 4, 5, 7, and 8 were characterized completely by spectral methods including 1 H-nmr and 13 C-nmr spectroscopy. The stereochemistry of the epoxide 8 was established unequivocally by X-ray crystallographic analysis

Relative and absolute configurations of two naturally occurring acetylenic spiroketal enol ether epoxides

The underground parts of Artemisia selengensis afforded a new C 14 acetylenic six-ring spiroketal enol ether epoxide. A closely related diastereomeric compound has been isolated previously, however, the relative configuration of the epoxy ring ( anti or syn to a reference oxygen) could not be established. The relative stereochemistries of the anti-syn pair were elucidated by 1H-lanthanide induced shifts and comparison of 13C NMR data. The absolute configurations were deduced via the corresponding carbinols using the method of Horeau. The results were confirmed by CD measurements and equilibration experiments of anti ⇌ syn pairs.

ChemInform Abstract: The Chemistry of Cyclic Vinyl Ethers. Part 4. Cyclization of Unsaturated Cyclic Vinyl Ether Epoxides.

AbstractDihydrofuran (Ia) and dihydropyran (Ib) are transformed into the unsaturated epoxides (V) which are cyclized to give the spirocyclic ketals (VI) and (VII) respectively.

The Chemistry of Cyclic Vinyl Ethers 4: Cyclization of Unsaturated Cyclic Vinyl Ether Epoxides

The Chemistry of Cyclic Vinyl Ethers 4: Cyclization of Unsaturated Cyclic Vinyl Ether Epoxides