- One-pot transformation of simple furans into 4-Hydroxy-2-cyclopentenones in water
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A highly efficient one-pot transformation of readily accessible furans into 4-hydroxy-2-cyclopentenones in H2O, using singlet oxygen as oxidant, has been developed.
- Kalaitzakis, Dimitris,Triantafyllakis, Myron,Alexopoulou, Ioanna,Sofiadis, Manolis,Vassilikogiannakis, Georgios
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p. 13201 - 13205
(2015/02/19)
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- Pyrimidine substituted-2,2-dimethylcyclopropane carboxylates useful for combating insect and acarine pests at a locus
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A compound of formula: STR1 wherein R2 represents an α-branched alkyl group containing from 3 to 6 carbon atoms, and R represents either (a) hydroxy, halo or alkoxy of up to six carbon atoms, or (b) the group --OR1 where R1 is the residue of an alcohol of formula R1 OH which forms an insecticidal ester with chrysanthemic acid, permethrin acid or cyhalothrin acid. The compounds have insecticidal and acaricidal properties.
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- Process for preparing 4-hydroxy-2-cyclopentenones
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A process for producing a compound of the formula: STR1 wherein R1 is a hydrogen atom, an alkyl group or an alkenyl group and R2 is an alkyl group, an alkenyl group or an alkynyl group, which comprises treating a compound of the formula: STR2 wherein R1 and R2 are each as defined above and R is a hydrogen atom or a lower alkyl group in the presence of an acidic substance and water.
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- Process for producing 4-cyclopentenones
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A 4-cyclopentenone of the formula: STR1 wherein R is a lower alkyl group, a lower alkenyl group or a lower alkynyl group and R' is a hydroxyl group or an aliphatic acyloxy group, provided that in case of the dl-form, R' is not a hydroxyl group and also that the substituent R at the 2-position and the methyl group at the 3-position take a cis-configuration in the dl-, d- or l-form.
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- Process for preparing cyclopentenolones
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A process for preparing cyclopentenolones of the formula STR1 wherein R1 is an alkyl group having not more than 6 carbon atoms, an alkenyl or alkynyl group having not more than 6 carbon atoms or a group of the formula: STR2 in which R2 is a hydrogen atom, a methyl group or a halogen atom directly from the corresponding furan-carbinols of the formula: STR3 wherein R1 is as defined above in a single step with an excellent yield, characterized in that the furan-carbinols are treated with water in the presence or absence of a catalyst.
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- NOVEL PHOTOPRODUCTS OF ALLETHRIN
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Two polar photoproducts of allethrin, allethrolone and allethronyl glyoxylate, were isolated and identified.The formation mechanisms of these were also discussed.
- Isobe, Naohiko,Matsuo, Masatoshi,Miyamoto, Junshi
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p. 861 - 864
(2007/10/02)
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- Process for producing 4-hydroxycyclopentenones
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A method of producing a 4-hydroxycyclopentenone represented by the formula, STR1 wherein R1 is an alkyl, alkenyl, alkynyl, cycloalkyl, thienyl, phenyl, p-methylbenzyl or benzyl group and R2 is an alkyl, alkenyl or alkynyl group having 6 or less carbon atoms, which comprises reacting a furylcarbinol compound of the formula, STR2 wherein R1 is as defined above, in the presence of an acid in a mixed solvent of water and an organic solvent, to obtain a cyclopentenone compound of the formula, STR3 wherein R1 is as defined above; reacting the cyclopentenone compound in the presence of an oxidizing agent to obtain a cyclopentendione compound of the formula, STR4 wherein R1 is a defined above; reacting the cyclopentendione compound with a Grignard reagent of the formula, wherein R2 is as defined above and X is chlorine, bromine or iodine atom, to obtain an oxocyclopentene compound of the formula, STR5 wherein R1 and R2 are as defined above; and reacting the cyclopentenone compound in the presence of a base. The 4-hydroxycyclopentenones are useful intermediates of agricultural chemicals.
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- Process for preparing cyclopentenolones
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A process for preparing cyclopentenolones in good yields which comprises treating a 4-hydroxy-4-R2 -5-R1 -2-cyclopentenone of the formula: STR1 wherein R1 is an alkyl group having not more than 6 carbon atoms, an alkenyl group having not more than 6 carbon atoms, an alkynyl group having not more than 6 carbon atoms or a group of the formula: STR2 (in which R3 is hydrogen, methyl or halogen) and R2 is a hydrogen atom or a methyl group, provided that when R2 is hydrogen, R1 is neither α-methylallyl nor α-methylpropargyl, in an aqueous medium in the presence or absence of a metal salt at a temperature of 20° to 200° C. to give the corresponding 2-R1 -3-R2 -4-hydroxy-2-cyclopentenone of the formula: STR3 wherein R1 and R2 are each as defined above.
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- Silyl Nitronates in Organic Synthesis. Routes to Heterocycles and Cyclopentanoids. Synthesis of Allethrolone and Calythrone. Acylation and Cyanohydroxylation of Double Bonds. An Exploratory Study
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Silyl nitronates are versatile reagents for the preparation of heterocycles by dipolar addition to double bonds.The intermediate isoxazolidines can be transformed to 2-isoxazolines, isoxazoles, furans, dihydrofuranones, pyrazoles, pyridazines and pyridazones.Reduction of 2-isoxazolines with Ti3+ leads to hydroxylated 1,4-diketones, which subsequently can be cyclized to cyclopentenones.Routes to calythrone, rethrolones, prostanoids and a number of naturally occurring dihydrofuranones are devised, as well as synthetic procedures for acylation, preparation of endiones, hydroxyacylation, cyanation and hydroxycyanation of double bonds.
- Andersen, Soeren H.,Das, Nalin B.,Joergensen, Ruth D.,Kjeldsen, Gunhild,Knudsen, Jes S.,et al.
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- A New Synthesis of Allethrolone
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A new synthesis of 2-allyl-4-hydroxy-3-methyl-2-cyclopenten-1-one, so called allethrolone is described, in which the Michael addition of 3-phenylthio-5-hexen-2-one to 1-nitro-1-propene followed by conversion of the nitromethyl group in the adduct to an aldehyde function is involved as the key step.
- Ono, Noboru,Tanabe, Yo,Tanikaga, Rikuhei,Kaji, Aritsune,Matsuo, Takashi
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p. 3033 - 3034
(2007/10/02)
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