- Electro-oxidation of hispanolone and anti-inflammatory properties of the obtained derivatives
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The electrochemical oxidation ((+)Pt-Ni(-)/NH4Br/MeOH) of the natural product hispanolone (1a) produced, in high yield (>95%), spiro-tetracyclic compounds 7a-7d as a result of the intramolecular addition of the C-9 hydroxyl group into the C-16 position with the simultaneous addition of a CH3O group at the C-15 position of the hispanolone furan moiety. After the electrochemical oxidation, an acid-catalyzed slow secondary reaction occurred producing the previously undescribed α-butenolide derivative, iso-Leopersin G (9). An anti-inflammatory study with the electro-synthesized compounds showed that 1a has higher anti-inflammatory properties with very low cytotoxicity (e.g., the inhibition of TPA-induced ear edema assay IC 50 = 1.05 μM/ear, positive control indomethacin IC50 = 0.27 μM/ear).
- Nieto-Mendoza, Elizabeth,Guevara-Salazar, Juan A.,Ramirez-Apan, Maria Teresa,Frontana-Uribe, Bernardo A.,Cogordan, Juan A.,Cardenas, Jorge
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Read Online
- Method of preparing 2,5-dimethoxy-2,5-dihydrofuran through biomass furan photocatalysis
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The invention discloses a method of preparing 2,5-dimethoxy-2,5-dihydrofuran through biomass furan photocatalysis. Currently, two traditional synthesis methods are available, wherein one is a chemicalsynthesis method which is implemented through a halogenation reaction between furan and elemental bromine, and the method is gradually eliminated because the reaction process is high in production cost and causes serious environmental pollution; and the other one is an electrolysis method, wherein the furan is subjected to electrolytic oxidation in a methanol solution, and the method has the defects that production cost is high, and electrolyte treatment is complicated. According to the method, biomass furan and methanol are used as raw materials, and the 2,5-dimethoxy-2,5-dihydrofuran is synthesized through a photocatalyst function in a room-temperature normal-pressure air atmosphere under visible light illumination. Through the method, operation is easy, production cost is greatly lowered, environmental pollution is avoided, and therefore the synthesis method has industrial development value and is efficient and environmentally friendly.
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Paragraph 0020-0039
(2020/02/20)
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- MANUFACTURING METHOD AND MANUFACTURING DEVICE FOR 2,5-DIALKOXY-2,5-DIHYDROFURAN OR THE LIKE
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PROBLEM TO BE SOLVED: To provide an efficient manufacturing method of 2,5-dialkoxy-2,5-dihydrofuran and/or a derivative from furan and/or a derivative thereof by photoelectrolytic oxidation using light energy. SOLUTION: There is provided a manufacturing method of 2,5-dialkoxy-2,5-dihydrofuran and/or a derivative by using a photoelectrolytic oxidation reaction for irradiating a light to a visible light-responsive photoanode electrode surface using furan represented by the formula (1) and/or a derivative thereof and alcohol represented by the formula (2). R1 and R2 are each independently H, a methyl group, an ethyl group or the like. R3OH (2), where R3 is an alkyl group of C4 or lower. SELECTED DRAWING: Figure 2 COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0026-0028; 0033; 0038; 0039
(2018/06/01)
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- A 2, 5 - furan two alkoxyl dihydro preparation method of compound
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The invention provides a preparation method of a 2,5-dialkoxyl dihydrofuran compound. The preparation method comprises the following steps: adding a furan compound shown by a formula I, alkyl alcohol shown by a formula III and an acid-binding agent into a reactor, stirring to react with chlorine, keeping the reaction temperature to be (-25)-25 DEG C, and reacting to obtain a 2,5-dialkoxyl dihydrofuran compound shown by a formula II, wherein in the formulas, R1, R2, R3 and R4 are independent hydrogen, halogen and C1-C5 alkyl, and R1 is a C1-C12 alkyl. The method provided by the invention is less in investment, low in energy consumption and high in efficiency; the reaction method is simple, and the operation is convenient and easy to implement; the raw materials are low in price, easy to obtain, and low in production cost; a byproduct is salt and can meet requirements on environmental protection; and the preparation method is suitable for performing industrial large-scale production of the 2,5-dialkoxyl dihydrofuran compound. Particularly, when a phase transfer catalyst is added into the method provided by the invention, the method also has the advantage that the yield of a target product is obviously improved.
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Paragraph 0023; 0024
(2017/08/25)
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- A practical microreactor for electrochemistry in flow
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A microreactor for electrochemical synthesis has been designed and fabricated. It has been shown that different reactions can be carried out successfully using simple protocols.
- Watts, Kevin,Gattrell, William,Wirth, Thomas
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experimental part
p. 1108 - 1114
(2011/10/05)
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- METHOD FOR PRODUCING ALKOXYLATED 2,5-DIHYDROFURAN BUT-2-ENE DERIVATIVES OR TETRA-1,1,4,4-ALKOXYLATED BUT-2-ENE DERIVATIVES
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The invention relates to a method for producing 2,5-dihydrofuran derivatives that are substituted in position 3 or 4, which carry a respective C1 to C6 alkoxy group (DHF alkoxy derivates I) in position 2 or position 5, or in both positions, or for producing 1,1,4,4-tetraalkoxy but-2-ene derivatives that are substituted in position 3 or 4, from 2-butene-1,4-diol derivatives of general formula (I), in which the groups R1 and R2 independently of one another represent hydrogen, C1 to C6 alkyl, C6 to C12 aryl or C5 to C12 cycloalkene or R1 and R2 together with the double bond, to which they are linked, form a C6 to C12 aryl group or a mono- or polyunsaturated C5 to C12 cycloalkyl group, or from a mixture of said 2-butene-1,4-diol derivatives and 2,5-dihydrofuran derivatives that are substituted in position 3 or 4 and carry a C1 to C6 alkoxy group in position 2 or 5, by electrochemical oxidation in the presence of a C1 to C6 monoalkyl alcohol.
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Page/Page column 9
(2008/06/13)
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- Development of a novel environmentally friendly electrolytic system by using recyclable solid-supported bases for in situ generation of a supporting electrolyte from methanol as a solvent: Application for Anodic methoxylation of organic compounds
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We have successfully developed a novel environmentally friendly electrolytic system using recyclable solid-supported bases for in situ generation of a supporting electrolyte from methanol as a solvent. It was found that solid-supported bases are electrochemically inactive at an electrode surface. It was also found that solid-supported bases dissociate methanol into methoxide anions and protons. Therefore, in the presence of solid-supported bases, it was clarified that methanol serves as both a solvent and a supporting electrolyte generated in situ. Anodic methoxylation of various compounds with solid-supported bases was carried out to provide the corresponding methoxylated products in good to excellent yields with a few exceptions. The methoxylated products and the solid-supported bases were easily separated by only filtration, and the desired pure methoxylated products were readily isolated simply by concentration of the filtrates. The separated and recovered solid-supported bases were recyclable for several times.
- Tajima, Toshiki,Fuchigami, Toshio
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p. 6192 - 6196
(2007/10/03)
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- Crenulacetal C, a marine diterpene, and its synthetic mimics inhibiting Polydora websterii, a harmful lugworm damaging pearl cultivation
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Polydora websterii, a harmful lugworm that has serious adverse effects on pearl oyster cultivation, was inhibited by a marine diterpene, crenulacetal C, isolated from the brown alga Dictyota dichotoma. Based on consideration of the activity-structure relationship, several synthetic compounds having an aromatic moiety with a hydroxyalkyl chain were prepared. Bioassay using larvae of Polydora websterii as well as pearl oysters (Pinctada fucata martians) suggested that 1-(2-ferrule)-1-nonanol was the most promising inhibitor.
- Takikawa, Mami,Uno, Kiyoko,Ooi, Takashi,Kusumi, Takenori,Akera, Shusaku,Muramatsu, Morimitsu,Mega, Hirohiko,Horita, Chie
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p. 462 - 466
(2007/10/03)
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- The binary reagent PhI(OAc)2-Mg(ClO4)2: a SET induced ring enlargement of furan derivatives into pyranones
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The binary reagent PhI(OAc)2-Mg(ClO4)2 is very efficient for a high conversion of (2-furyl)-1-alcohols into puranones. The reaction mechanism can be explained in terms of a SET process, with the generation of a cation radical as key intermediate.
- De Mico,Margarita,Piancatelli
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p. 3553 - 3556
(2007/10/02)
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- Concurrent Anodic Cyanation and Methoxylation of Methylated Furans. Oxidation Potential and Reactivity, and Stereochemical Control of Addition
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The potentiostatic electrooxidation of a series of methyl-substituted furans was performed in MeOH that contains NaCN at a Pt anode in a divided cell.In all instances, the 1,4-additions of cyano and/or methoxyl group(s) across the furan ring were achieved.Replacement of an aromatic hydrogen by a cyano group occured concurrently in some cases.The relative rates of cation radicals toward two different nucleophiles (CN- ion and the solvent MeOH) (or the MeO- ion as a result of the equilibrium between CN- ion and the solvent MeOH) at the electrode surface were determined from the yields of products by using the rate expressions of competitive reactions.There is a linear correlation between the relative reactivity of the furans (on a log scale) and their oxidation potential.The ratio of stereoisomers formed in an electrooxidation of 2,5-dimethylfuran (2,5-DMF) changes with addition of adsorbable compound as well as substrate concentration and this is thought to be due to the influence of concentration (or coadsorbate) on substrate orientation in the adsorption layer.
- Yoshida, Kunihisa,Fueno, Takayuki
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p. 229 - 240
(2007/10/02)
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