Epoxy Derivatives Research Articles

Epoxidation of sesquiterpene lactones tourneforin and ludartin

Epoxy derivatives of the sesquiterpene lactones ludartin and tourneforin were synthesized. Their structures were elucidated using spectral data and x-ray structure analysis.

N-[4-(arylpiperazin-1-yl)butyl]bicyclo[2.2.1]hept-5-ene-endo-2,endo-3-dicarboximides and Their Epoxy Derivatives. Synthesis and affinity for 5-HT1a receptors

New ligands for 5-HT1A serotonin receptors, N-[4-(4-arylpiperazin-1-yl)butyl]bicyclo[2.2.1]hept-5-ene-endo-2,endo-3-dicarboximides and their epoxy derivatives, were synthesized, and their affinity for 5-HT1A receptors was estimated at 16.2 ± 2.0 to 0.60 ± 0.08 nM.

Synthesis of some electron-rich aryl(hetaryl)oxiranes under phase-transfer and homogeneous conditions

Reactions of mono-, di-, and trimethoxybenzaldehydes with trimethylsulfonium methyl sulfate readily occur under mild homogeneous and heterogeneous phase-transfer conditions to give the corresponding aryloxiranes whose yields are comparable with those typical of severe Corey-Chaykovsky reaction conditions. The phase-transfer version ensures better purity of the epoxy derivatives and is the only possible way of preparing 1-methyl-3-(oxiran-2-yl)-1H-indole.

A Radical Clock for Reactions of Epoxy Derivatives Induced by Titanocene Chloride

A new radical clock based on pinene derivatives has been designed to measure the radical cyclization rate onto cyano and carbonyl groups and the radical elimination rate of OR and CN. In this system, the known rate constant of cyclobutylcarbinyl radical cleavage is used as the internal clock. At room temperature, the cyclization rate constants for 4-exo and 5-exo processes onto nitrile and aldehyde carbonyl groups are in the order of 107 to 108 s-1. The radical elimination rate constants for CN, OH, OCHO, and OAc are in the order of 105 to 108 s -1. © Georg Thieme Verlag Stuttgart.

Identification of Novel C20 and C22 Trienoic Acids from Arctiid and Geometrid Female Moths that Produce Polyenyl Type II Sex Pheromone Components

Gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (EAD) analyses of the sex pheromone extract from a wasp moth, Syntomoides imaon (Lepidoptera: Arctiidae: Syntominae), showed that virgin females produced (Z,Z,Z)-3,6,9-henicosatriene and (Z,Z,Z)-1,3,6,9-henicosatetraene with a trace amount of their C(20) analogs. Identification of the chemical structures was facilitated by comparison with authentic standards and the double-bond positions were confirmed by dimethyl disulfide derivatization of monoenes produced by a diimide reduction. In a field test in the Yonaguni-jima Islands, males of the diurnal species were captured in traps baited with a 1:2 mixture of the above-described synthetic C(21) polyenes. Lipids were extracted from the abdominal integument and its associated oenocytes and peripheral fat bodies. Following derivatization, fatty acid methyl esters (FAMEs) were fractionated by HPLC equipped with an ODS column, and methyl (Z,Z,Z)-11,14,17-icosatrienoate and (Z,Z,Z)-13,16,19-docosatrienoate were identified by GC-MS. These novel C(20) and C(22) acid moieties are longer-chain analogs of linolenic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid. They are presumed to be biosynthetic precursors of the S. imaon pheromone because the C(21) trienyl component might be formed by decarboxylation of the C(22) acid. On the other hand, the C(20) acid, but not the C(22) acid, was found in FAMEs of Ascotis selenaria cretacea (Lepidoptera: Geometridae), which secretes C(19) pheromone components, (Z,Z,Z)-3,6,9-nonadecatriene and the monoepoxy derivative, indicating that different systems of the chain elongation might play an important role in developing species-specific communication systems mediated with polyunsaturated hydrocarbons and/or epoxy derivatives, components of Type II lepidopteran sex pheromones.

Synthesis and Chemical Characterization of Hydrocarbons with a 6,9,11-, 3,6,9,11-, or 1,3,6,9-Polyene System, Pheromone Candidates in Lepidoptera

Lepidopteran Type II sex pheromones are mainly composed of 6,9-dienes, 3,6,9-trienes, and their epoxy derivatives, which are biosynthesized from linoleic and linolenic acids by the species in some families of higher Lepidoptera. To investigate further structural modifications on this theme, we synthesized polyunsaturated hydrocarbons with a C(17)-C(21) chain, which included an extra double bond. Using the Wittig reaction, (Z,Z,E)-6,9,11-trienes and (Z,Z,Z,E)-3,6,9,11-tetraenes were synthesized from (E)-2-alkenals with appropriate carbon chains, and (Z,Z,Z)-1,3,6,9-tetraenes were synthesized from 3-hexyn-1,6-diol. The gas chromatography-mass spectrometry (GC-MS) analysis of each synthetic polyene, whose chemical structure was confirmed by (1)H NMR and (13)C NMR, revealed some characteristic fragment ions reflecting the positions of the double bonds, i.e., m/z 79, 110, 163, and M-85 of the 6,9,11-trienes, m/z 79, 108, and M-82 of the 3,6,9,11-tetraenes, and m/z 79, 91, 106, and M-54 of the 1,3,6,9-tetraenes. Because the determination of the unsaturated positions is difficult to accomplish by chemical derivatization with a limited amount of natural pheromones, these diagnostic ions found in authentic samples would help identify the hydrocarbons in a pheromone extract. Furthermore, we carried out field screening tests of these polyenes in forests in Japan, and documented the attraction of four geometrid species in Tokyo and one noctuid species in the Iriomote Islands.

Oxidation reactions of some natural volatile aromatic compounds: anethole and eugenol

trans-Anethole [1-methoxy-4-(trans-prop-1-en-1-yl)benzene] was isolated from anise seed oil (Pimpinella anisum). Its photochemical oxidation with hydrogen peroxide gave the corresponding epoxy derivative together with 4-methoxybenzaldehyde. The thermal oxidation of trans-anethole with 3-chloroperoxybenzoic acid at room temperature resulted in the formation of dimeric epoxide, 2,5-bis(4-methoxyphenyl)-3,6-dimethyl-1,4-dioxane, as the only product. Photochemical oxygenation of trans-anethole in the presence of tetraphenylporphyrin, Rose Bengal, or chlorophyll as sensitizer led to a mixture of 1-(4-methoxyphenyl)prop-2-en-1-yl hydroperoxide and 4-methoxybenzaldehyde. Eugenol was isolated from clove oil [Eugenia caryophyllus (Spreng.)]. It was converted into 2-methoxy-4-(prop-2-en-1-yl)phenyl hydroperoxide by oxidation with hydrogen peroxide under irradiation. Thermal oxidation of eugenol with 3-chloroperoxypenzoic acid at room temperature produced 2-methoxy-4-(oxiran-2-ylmethyl)phenol, while sensitized photochemical oxygenation (in the presence of Rose Bengal or chlorophyll) gave 4-hydroperoxy-2-methoxy-4-(prop-2-en-1-yl)cyclohexa-2,5-dien-1-one.

Oxidation studies on some natural monoterpenes: Citral, pulegone, and camphene

Citral extracted from Cymbopogon citratus (Gramineae) was subjected to photochemical epoxidation with hydrogen peroxide to obtain a mixture of epoxy derivatives at the C2=C3 and C6=C7 double bonds. The thermal oxidation of citral with m-chloroperoxybenzoic acid at room temperature gave only the corresponding 6,7-epoxy derivative as a mixture of E and Z isomers with respect to the C2=C3 double bond. Photosensitized oxygenation of citral in the presence of tetraphenylporphyrin, Rose Bengal, or chlorophyll lead to a mixture of two isomeric hydroperoxides, (2E)-6-hydroperoxy-3,7-dimethylocta-2,7-dienal and (2E,5E)-7-hydroperoxy-3,7-dimethylocta-2,5-dienal. Epoxidation of pulegone isolated from Penny royal oil (Mentha pulegium, Lamiaceae) with hydrogen peroxide under irradiation with a sodium lamp lead to a mixture of cis- and trans-isomeric 2,2,6-trimethyl-1-oxaspiro[2.5]octan-4-ones, whereas under conditions of photosensitized oxygenation two hydroperoxide derivatives, 2-(1-hydroperoxy-1-methylethyl)-5-methylcyclohex-2-en-1-one and 2-hydroperoxy-5-methyl-2-(1-methylethenyl)cyclohexan-1-one, were also formed. Camphene reacted with hydrogen peroxide under irradiation to give a mixture of the corresponding endo- and exo-epoxy derivatives and camphor, while its thermal oxidation with m-chloroperoxybenzoic produced only the two former.

Reactions of Bi-, Tri-, and tetracyclic amines with succinic anhydride

Succinic anhydride reacted with cage-like amines {bicyclo[2.2.1]hept-5-en-exo-and-endo-2-yl-methanamines, 2-(bicyclo[2.2.1]hept-5-en-endo-2-yl)ethanamine, exo-5,6-epoxybicyclo[2.2.1]heptan-exo-2-yl-methanamine, tetracyclo[6.2.1.13,6.02,7]dodec-9-en-endo-4-ylmethanamine, 1-(bicyclo[2.2.1]heptan-2-yl)ethanamine, and 4-azatricyclo[5.2.1.02,6]dec-8-ene} to give the corresponding amido acids having a cage-like fragment. The latter were converted into carboximides by the action of hexamethyldisilazane in boiling benzene in the presence of zinc(II) chloride and then into epoxy derivatives. The structure of the newly synthesized compounds was confirmed by IR and NMR spectroscopy.

Study on cross‐linking reaction between acrylic resin and epoxy derivative in over coating layer materials for TFT panel

AbstractA photoactive over coating layer (OCL) material was prepared by mixing methacrylate copolymer resin, epoxy, and photoactive compounds, separately. The OCL material was found to show long shelf life at room temperature. However, serious lowering of the transparency of the OCL material was caused by post‐baking after alkali development. Microscopic and near infrared spectroscopic studies revealed that the phase separation between the hydrophilic copolymer resin and hydrophobic epoxy compound brought about the formation of wrinkly surface during the post‐baking after the alkali development, and consequently the transparency was lowered by light scattering due to the wrinkly surface. The carboxylic acid derivatives with long alkyl groups were effective for improvement of the transparency without shortening of the shelf life. Copyright © 2008 John Wiley & Sons, Ltd.

Methods and mechanisms of epoxy compounds reduction

Analysis was performed of reduction processes of epoxy derivatives obtained from unsaturated compounds belonging to various groups: alkenes, cycloalkenes, spiroalkanes, and substituted norbornenes. The regio- and stereochemistry was discussed of reactions between epoxides and complex metal hydrides, of catalytic hydrogenation, and some other processes. The mechanisms were considered of the reduction reactions, in particular, those involving radical and ion radical intermediates.

Epoxyalkenyl sex pheromones produced by female moths in highly evolved groups: biosynthesis and its endocrine regulation

Polyunsaturated hydrocarbons with a C 17 -C 23 straight chain and the epoxy derivatives constitute a second major class of lepidopteran sex pheromones and are referred to as Type II pheromones. While regionspecific epoxidation proceeds in a pheromone gland, the hydrocarbons are biosynthesized from dietary polyunsaturated fatty acids outside the pheromone gland and transported into the gland after association with lipophorin. In vivo as well as in vitro experiments using Japanese giant looper (Ascotis selenaria cretacea, Geometridae) demonstrated that pheromone biosynthesis-activating neuropeptide (PBAN) accelerated precursor uptake by the gland but not the biosynthetic step, which was contrast with the biosynthesis of Type I pheromones. The neuropeptide of A. s. cretacea, Assc-PBAN, was characterized to clarify its mode of unique action.

Synthetic Use Of Epoxy-Sugar Nucleosides

Preparation of 1′,2 ′-, 3 ′,4 ′-, and 4 ′,5 ′-epoxy derivatives of nucleosides and their use for the stereoselective synthesis of 1′- and 4 ′-branched analogues are described.

Hydrogen peroxide-or sodium hypochlorite-induced bromination of 1-arylbut-2-enes

Bromination of 1-arylbut-2-enes in the system [HBr or NaBr (KBr)-HX]-H2O2 (or NaOCl) under relatively mild conditions leads to electrophilic addition of bromine or hypobromous acid at the side-chain double bond. Under more severe conditions, the process is accompanied by bromination of the aromatic ring. Treatment of the title compounds with peroxy acids (RCOOH-H2O2) gives the corresponding epoxy derivatives which react with HBr and oxygen-containing nucleophiles to produce α-bromo alcohols, diols, and diol acetates.

Synthetic Access to New Pyridone Derivatives through the Alkylation Reactions of Hydroxypyridines with Epoxides

General methods for the preparation of a variety of pyridone and oxypyridine derivatives are described. 2‐,3‐,4‐Hydroxy pyridine and 2‐pyridinemethanol were alkylated with ethylene‐, propylene‐, and stryrene‐oxide and epichlorohydrin in the presence of different Lewis acids as a catalyst. The best yield of 3a was achieved in the presence of CdI2/BF3 · OEt2. The corresponding pyridone derivatives (3a–d, 7a–d) were obtained from the reaction of 2‐and 4‐hydroxypyridine with oxiranes in good yields, whereas oxypyridine derivatives (5a–d, 9a,b) were obtained from reactions of 3‐hydroxypyridine and 2‐pyridinemethanol with oxiranes. Chlorohydrines (3d, 5d, 7d) were easily converted to corresponding epoxy derivatives (10, 11, 12) in basic medium; then amino alcohols (13–17) were obtained from the reaction of these epoxy derivatives with amines.

Studies of the chemical composition of birch bark extracts (Cortex betula) from the Betulaceae family

This report presents the results obtained from chemical studies of the composition of dried birch bark extracts (DBBE) from Betula pubescens Ehrh. analyzed by GLC, HPLC, and IR and PMR spectroscopy. The extract contained the following groups of natural compounds: terpenoids (75.2%) and their esters (fatty acid esters of betulinol and lupeol, 4.4%), ether oils (0.08%), hydrocarbons (6.3%) and their epoxides (1.0%), steroids (β-sitosterol, 2.7%), tannins (2.1%), flavonoids (1.56%-mainly kaempferol, its 7-methyl ester, quercetin, the 4-methyl ester of naringenin, etc.), hydroxycoumarins (0.85%-umbelliferone, esculetin, etc.), and a number of unidentified compounds (about 4.0%). The major components of DBBE were triterpenoids and hydrocarbons. Preparative chromatographic separation of fractions containing triterpenoids and hydrocarbons yielded isolated samples which allowed the following compounds to be identified: the terpenoids betulinol, isobetulinol, lupeol, lupenone, betulonic aldehyde, betulonic acid, betulinic acid, and platanic acid, and the hydrocarbons α-santalene, β-trans-bergamotene, and α-trans-bergamotene, and their epoxy derivatives. The chemical composition of DBBE varied depending on the preparation method used, this particularly affecting the content of the major component betulinol, which varied from 54 to 82%. These studies led to the development of a contemporary preparative technology for betulinol with a yield of 95%, along with production of many of its acyl derivatives (for example, the diacetate, succinate, benzoate, etc.) with quite high yields (95–98%); betulinic acid was synthesized in mild conditions with a yield of at least 99.0%. These compounds are currently subject to pharmacological studies.

Synthesis of Hydroxy, Epoxy, Nitrato and Methoxy Derivatives of Tetralins and Naphthalenes.

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Preparation and photophysical behaviors of fluorescent chitosan bearing fluorescein: Potential biomaterial as temperature/pH probes

AbstractA novel method for attaching fluorescein (via its epoxy derivative) to water‐soluble chitosan, and the temperature/pH‐sensitive qualities of fluorescence were investigated. 3‐Epoxypropoxy fluorescein (EPF) was firstly synthesized by the reaction between fluorescein and epichlorohydrin, and then water‐soluble chitosan bearing fluorescein (CS‐EPF) was prepared via ring‐opening reaction with EPF. They were characterized by the methods of 1H NMR, MS, IR, UV–Vis, and luminescence spectra, respectively. The chemiluminescent and photophysical behaviors of EPF and CS‐EPF were studied in detail. The results showed that the fluorescent chitosan could still provide temperature and pH sensitivities similar to that of fluo‐ rescein, achieving better long‐term stability and fast equilibrium response. CS‐EPF had an excellent linear response between relative fluorescence intensity and temperature in the range of 0–60°C and two linear relationships between relative fluorescence intensity and pH in 0.0–4.14 and 8.15–13.20, respectively. This investigation may provide a convenient way to prepare low‐cost and multifunctional macromolecule biomaterial to probe pH and temperature in biological systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3960–3966, 2007

Curing properties of cycloaliphatic epoxy derivatives

In the cationic ring-opening polymerization of cyclic ethers, three major factors, i. e. ring strain, basicity and steric hindrance, are known to govern the reactivity. Considering from these three factors, cycloaliphatic epoxides seem to be the best candidate for the high performance formulations. In the commercial applications, 3,4-epoxycyclohexyl-3′,4′-epoxycyclohexene-carboxylate (ECC) is widely used as cycloaliphatic epoxy monomer. In ECC polymerization, the possibility of ester group participation was pointed out, which resulted in lower reactivity. The negative effect of ester group seems to be very important issue for improved reactivity. In this study, to clarify the effect of the ester group on the cationic polymerization, two di-functional monomers, 2,2-bis-(3,4-epoxycyclohexyl)-propane (CADE-1) and 3,3′-bicyclohexene-3,3′,4,4′-diepoxide (CADE-2), were selected as candidate for no-ester monomers and their reactivity in the photo-initiated cationic polymerization was investigated. Using photo-DSC and real time DRA method, reactivity comparison of them with ECC was conducted. High curing rate of CADEs, especially for low viscous CADE-2, was confirmed. The curing rate of highly viscous CADE-1 was effectively accelerated by addition of low viscous oxetane monomer.

Azabrendanes IV. Synthesis and characterization of N-(alkyl- and benzylsulfonyl)- exo-2-hydroxy-4-azatricyclo[4.2.1.0 3,7]nonanes

exo- and endo-5-Aminomethylbicyclo[2.2.1]hept-2-enes have been obtained from stereoisomeric exo- and endo-5-cyanobicyclo[2.2.1]hept-2-enes and the corresponding sulfonamides were obtained through reaction of amines with methyl-, n-propyl-, n-butyl-, benzyl-, and cyclohexylsulfonyl chlorides. From the stereoisomeric sulfonamides with peroxy acids, various products were obtained: exo-sulfonamides were transformed into epoxy derivatives, and, in contrast, most of the endo-stereoisomers underwent heterocyclization resulting in substituted exo-2-hydroxy-4-azatricyclo[4.2.1.0 3,7]nonanes. The type of the products obtained did not depend on the type of peroxy acid used (peroxyacetic, peroxyphthalic, and m-chloroperoxybenzoic one). In contrast to other endo-sulfonamides, N-(cyclohexylsulfonyl)- endo-5-aminomethylbicyclo[2.2.1]hept-2-ene in reaction with peroxyacetic acid did not undergo heterocyclization, probably, due to steric factors. The structure and stereochemical homogeneity of the sulfonamides and the structure of the products of their oxidation with peroxy acids were confirmed by spectroscopic methods. The molecular structure of N-(cyclohexylsulfonyl)- endo-5-aminomethyl- exo-2,3-epoxybicyclo[2.2.1]heptane was determined by X-ray diffraction analysis. The mechanism of the intramolecular heterocyclization reaction of N-substituted endo-5-aminomethyl- exo-2,3-epoxybicyclo[2.2.1]heptanes was studied at the BHandHLYP/6-31G(d) level of theory.