cas 504-02-9, 1,3-Cyclohexanedione | Articles data

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Method for preparing 1, 3-cyclohexanedione
The invention discloses a method for preparing 1, 3-cyclohexanedione. The method comprises the following steps: 1) dissolving acetylacetone and a catalyst in a solvent, adding acrylate into a constant-pressure dropping funnel, and dropwise adding acrylate into a reaction system, after drop-by-drop adding, heating to 60-80 DEG C, and continuously reacting for 0.5-1 hour; and 2) after the reaction is finished, cooling to 40 DEG C, adding a solid condensing agent, heating the reaction liquid to 40-50 DEG C, continuously reacting for 1-1.5 hours, concentrating under reduced pressure to remove the solvent and methyl acetate and other low-boiling-point byproducts generated by the reaction, then adding a small amount of water, adjusting the pH value to 1-2 by using hydrochloric acid (1.1-1.2 equivalent), cooling to separate out a product, centrifuging, leaching by using a small amount of ice water, carrying out pulping treatment by using ethyl acetate, filtering and drying to obtain the 1, 3-cyclohexanedione product.
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Paragraph 0026-0032

(2021/09/04)

Method for synthesizing 1,3-cyclohexanedione by utilizing platinum-carbon catalytic reaction
The invention discloses a method for synthesizing 1,3-cyclohexanedione by utilizing a platinum-carbon catalytic reaction, and belongs to the technical field of chemical industry. The method comprisesthe following steps: mixing and dissolving resorcinol and sodium hydroxide into deionized water, carrying out a reaction at a temperature of 5-15 DEG C to prepare a resorcinol solution, carrying out heat preservation and pressure maintaining treatment for 45-90 minutes, adding a platinum-carbon catalyst, stirring, carrying out a reaction for 15 to 20 hours, obtaining a black solid after the metalions in the solution are completely reduced, and washing sequentially with distilled water and ethanol to obtain a 1,3-cyclohexanedione crude product. According to the invention, the platinum-carbon catalyst adopted as a reduction reaction catalyst has great economic advantages and great safety advantages compared with the traditional Raney nickel catalyst, the risk easily occurring during the production process is avoided, and the yield and the quality of the product are improved.
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Paragraph 0014-0024

(2020/04/06)

Preparation method of 1,3-cyclohexanedione
The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione comprises the following steps: with 1,3-acetonedicarboxylic ester and acrylate as raw materials, carrying out condensation and cyclization under the action of a base catalyst to prepare an intermediate; carrying out hydrolysis decarboxylation on the intermediate to obtain a crude product; and recrystallizing the crude product to obtain the 1,3-cyclohexanedione. The preparation method of the 1,3-cyclohexanedione hasthe advantages that process conditions are convenient to realize, post-treatment operation process is simple, yield is as high as 90.9%, reaction selectivity is high, production efficiency is high, operation safety is high, pollution is small, and the preparation method is suitable for industrial scale production.
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Paragraph 0013; 0026-0030; 0036-0045; 0061

(2020/06/09)

Preparation method of 1,3-cyclohexanedione
The invention relates to the field of organic synthesis, and discloses a preparation method of 1,3-cyclohexanedione. The method comprises the following steps: 1, in the presence of water, hydrogenating resorcinol to obtain a reaction solution containing a compound represented by the following formula (1), acidifying the reaction solution to obtain an acidified solution, and crystallizing the acidified solution to obtain a 1,3-cyclohexanedione product and an acidified mother liquor; 2, in the presence of an organic solvent, enabling the acidified mother liquor to be in contact with a complexingagent to complex 1,3-cyclohexanedione with the complexing agent, and obtaining an organic phase; 3, making the organic phase obtained in the step 2 contact the reaction solution, adjusting the pH value to 7-14 so as to make the 1,3-cyclohexanedione be dissociated from the complexing agent, and obtaining a water phase; and 4, adjusting the pH value of the water phase obtained in the step 3 to 1.0-2.5, and carrying out solid-liquid separation to obtain the 1,3-cyclohexanedione product. The preparation method disclosed by the invention has the advantages of high purity and high yield of the prepared 1,3-cyclohexanedione.
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Paragraph 0068-0095

(2020/07/13)

Rapid and Multigram Synthesis of Vinylogous Esters under Continuous Flow: An Access to Transetherification and Reverse Reaction of Vinylogous Esters
An environmentally benign approach for the synthesis of vinylogous esters from 1,3-diketone and its reverse reaction under continuous-flow has been developed with alcohols in the presence of inexpensive Amberlyst-15 as a catalyst. This methodology is highly selective and general for a range of cyclic 1,3-dicarbonyl compounds which gives a library of linear alkylated and arylated vinylogous esters in good to excellent yield under solvent and metal free condition. Furthermore, the long-time experiment in a continuous-flow up to 40 h afforded 8.0 g of the vinylogous ester with turnover number (TON) = 28.6 and turnover frequency (TOF) = 0.715 h-1 using Amberlyst-15 as a catalyst. Furthermore, a continuous-flow sequential transetherification of vinylogous esters with various alcohols has been achieved in high yield. Reversibly, this vinylogous ester was deprotected or hydrolyzed into ketone using environmentally benign water as a solvent and Amberlyst-15 as a catalyst under continuous-flow process.
Mohanta, Nirmala,Chaudhari, Moreshwar B.,Digrawal, Naveen Kumar,Gnanaprakasam, Boopathy
p. 1034 - 1045
(2019/05/24)

Reversible chemoselective transetherification of vinylogous esters using Fe-catalyst under additive free conditions
An additive/Br?nsted acid/base free, highly efficient and chemoselective transetherification of electron deficient vinylogous esters and water mediated de-alkylation using an earth-abundant Fe-catalyst under very mild reaction conditions is described. This reaction is highly selective to primary alcohols over secondary alcohols, has good functional group tolerance, is scalable to gram scale and a purification free sequential transetherification in a continuous flow mode is demonstrated.
Parvathalu, Nenavath,Agalave, Sandip G.,Mohanta, Nirmala,Gnanaprakasam, Boopathy
p. 3258 - 3266
(2019/03/26)

Method for preparing 1,3-cyclohexanedione through gas-phase hydrogenation of resorcinol
The invention provides a method for preparing 1,3-cyclohexanedione through gas-phase hydrogenation of resorcinol. The method comprises the following steps: dissolving resorcinol in benzene, then subjecting the dissolved resorcinol to direct vaporization, and mixing the vaporized resorcinol with hydrogen; allowing a mixture obtained in the previous step to pass through a fixed-bed reactor filled with an activated carbon-supported palladium catalyst at a mass space velocity of 0.1/h to 0.7/h, and controlling a molar ratio of hydrogen to phenol to be 2/1 to 10/1, a reaction temperature to be 180-280 DEG C and a reaction pressure of 1.0-2.0 MPa; and condensing a product obtained in the previous step with a condenser so as to obtain the hydrogenation product, i.e., 1,3-cyclohexanedione. As themethod is used for preparation of 1,3-cyclohexanedione, the conversion rate of resorcinol is up to 99.9%, and the selectivity of 1,3-cyclohexanedione is up to 97.8%.
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Paragraph 0020; 0022; 0023; 0026; 0030; 0034; 0038; 0042

(2018/11/03)

Palladium graphene selective catalytic hydrogenation process for preparing 1, 3 - Cyclohexanedione method (by machine translation)
The invention discloses a palladium graphene selective catalytic hydrogenation process for preparing 1, 3 - Cyclohexanedione method: in the reactor, adding catalyst palladium graphene, raw material resorcinol soluble in the solvent dichloromethane solution, the hydrogen gas, the hydrogen pressure is 0.1 - 2 mpa, temperature is 20 - 60 °C reaction under the condition of 0.5 - 3h after, processing reaction liquid to obtain product 1, 3 - Cyclohexanedione; this invention adopts the palladium graphene selective catalytic hydrogenation resorcinol preparing 1, 3 - Cyclohexanedione method, with the traditional process for preparing 1, 3 - Cyclohexanedione processes of the prior art, avoids the use of large amount of organic and inorganic salt, the operation process is simple and easy, high conversion rate and selectivity, has very high innovative and industrial application value. (by machine translation)
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Paragraph 0038; 0046; 0053; 0060; 0067; 0074; 0077-0081

(2017/08/25)

1,3-cyclohexanedione preparation method
The invention discloses a 1,3-cyclohexanedione preparation method, which comprises: (1) salt forming: mixing and dissolving resorcinol and sodium hydroxide in deionized water, and carrying out a reaction at a temperature of 5-15 DEG C; (2) hydrogenation reducing: transferring the salt-forming solution obtained in step (1) into a hydrogenation kettle, adding a platinum-carbon catalyst, introducing hydrogen gas after completing the displacement, stirring, and carrying out a reaction, wherein the reaction pressure is 1.2-1.5 MPa, and the reaction temperature is 95-105 DEG C; and (3) acidification: acidifying the filtrate obtained in step (2) at a temperature of 0-15 DEG C. According to the present invention, the preparation method has advantages of low risk, high application times, high yield, and high product purity.
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Paragraph 0053-0063

(2017/05/27)

Transformation of the Herbicide Sulcotrione into a Root Growth Enhancer Compound by Sequential Photolysis and Hydrolysis
Xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl (1), the main product of sulcotrione phototransformation on plant leaves, was slowly hydrolyzed into 2-hydroxy-4-methylsulfonylbenzoic acid (2) and 1,3-cyclohexanedione (3) in aqueous solution. Interestingly, the rate of hydrolysis was significantly enhanced in the presence of roots of monocotyledonous plants, while the same treatment showed adverse effects on broadleaf weeds. Root growth enhancement varied according to the plant species and concentrations of compound 2, as shown with Zea mays roots. Compound 2 is a derivative of salicylic acid that is known to be a plant signaling messenger. Compound 2 was, therefore, able to mimic some known effects of this phytohormone. This work showed that a pesticide like sulcotrione was transformed into a compound exhibiting a positive impact on plant growth. This study exemplified a rarely reported situation where chemical and biological chain reactions transformed a xenobiotic into a compound exhibiting potential beneficial effects.
Goujon, Eric,Maruel, Sandra,Richard, Claire,Goupil, Pascale,Ledoigt, Gérard
p. 563 - 569
(2016/02/05)

Highly potent HIV-1 protease inhibitors with novel tricyclic P2 ligands: Design, synthesis, and protein-ligand X-ray studies
The design, synthesis, and biological evaluation of a series of HIV-1 protease inhibitors incorporating stereochemically defined fused tricyclic P2 ligands are described. Various substituent effects were investigated to maximize the ligand-binding site interactions in the protease active site. Inhibitors 16a and 16f showed excellent enzyme inhibitory and antiviral activity, although the incorporation of sulfone functionality resulted in a decrease in potency. Both inhibitors 16a and 16f maintained activity against a panel of multidrug resistant HIV-1 variants. A high-resolution X-ray crystal structure of 16a-bound HIV-1 protease revealed important molecular insights into the ligand-binding site interactions, which may account for the inhibitor's potent antiviral activity and excellent resistance profiles.
Ghosh, Arun K.,Parham, Garth L.,Martyr, Cuthbert D.,Nyalapatla, Prasanth R.,Osswald, Heather L.,Agniswamy, Johnson,Wang, Yuan-Fang,Amano, Masayuki,Weber, Irene T.,Mitsuya, Hiroaki
p. 6792 - 6802
(2013/10/01)

METHOD FOR MANUFACTURING KETONE
A method for manufacturing a ketone, includes oxidizing an internal olefin or a cyclic olefin having a functional group containing a hetero atom and one carbon-carbon double bond or more at a position other than terminals of a molecule thereof in an amide-based solvent in the presence of water, a palladium catalyst, and molecular oxygen, without oxidizing the functional group, thereby bonding an oxo group to at least one of the carbon atoms constituting the carbon-carbon double bond. The amide-based solvent is represented by formula (1): wherein R1 represents an alkyl group having 1 to 4 carbon atoms; R2 and R3 each independently represent an alkyl group having 1 to 4 carbon atoms or an aryl group; and when R1 and R2 are alkyl groups, R1 and R2 may be bonded to each other to form a ring structure.
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Page/Page column 9

(2012/08/08)

Consecutive Michael-claisen process for cyclohexane-1,3-dione derivative (CDD) synthesis from unsubstituted and substituted acetone 1
A long-existing problem of cyclohexane-1,3-dione derivatives (CDD) synthesis from unreactive acetone through consecutive Michael-Claisen process was solved under this study. The practical applicability of this process was tested for a novel compound ethyl 3-(2,4-dioxocyclohexyl)propanoate for up to 20-gram scale. Furthermore, the scope of different acetone derivatives was investigated and resulted with similar consecutive Michael-Claisen process for CDD synthesis. The reaction exhibited remarkable regioselectivity in Michael addition followed by Claisen cyclization. In this process high substrate selectivity was observed for CDD synthesis following consecutive double-Michael-Claisen and Michael-Claisen cyclization. Georg Thieme Verlag Stuttgart · New York.
Sharma, Dharminder,Shil, Arun K.,Singh, Bikram,Das, Pralay
supporting information; experimental part
p. 1199 - 1204
(2012/06/15)

Synthesis and deprotection of 1,3-Dithianes and 1,3-Dithiolanes by polyphosphoric acid
A simply, mild and efficient method for the deprotection of 1,3-dithianes and 1,3-dithiolanes to their corresponding carbonyl compounds using a mixture of polyphosphoric acid and acetic acid at 20-45 °C is reported.
Jin, Yong-Sheng,Zhang, Wei,Zhang, Da-Zhi,Qiao, Li-Ming,Wu, Qiu-Ye,Chen, Hai-Sheng
experimental part
p. 1117 - 1119
(2011/12/16)

Synthesis of enaminones in aqueous media using catalytic dilute HCl
(Chemical Equation Presented) A green and convenient approach to the synthesis of β-enaminones from aromatic amines and 5-substituted-1,3- cyclohexanedione in the presence of dilute hydrochloric acid (30 mmol=L) as a catalyst in solvent-free media is described. This method provides several advantages such as environmental friendliness, low cost, good yields, and simple workup procedure. Copyright Taylor & Francis Group, LLC.
Cui, Bin,Wang, Rui-Hua,Chen, Li-Zhuang,Jin, Yan,Han, Guang-Fan
scheme or table
p. 1064 - 1070
(2011/04/26)

Studies towards the synthesis of 13C-labelled anthocyanins
The anthocyanins are a class of polyphenols found in nature, which are widely distributed throughout the plant kingdom and are thought to possess antioxidant properties. Methodology previously developed in our group for the regioselective placement of 13C-atoms into aromatic rings is being applied to the synthesis of 13C-labelled anthocyanins-namely cyanidin-3-glucoside and delphinidin-3-glucoside. Copyright
Marshall, Laura J.,Cable, Karl M.,Botting, Nigel P.
scheme or table
p. 315 - 318
(2011/05/02)

Aqueous Iodine(III)-mediated stereoselective oxidative cyclization for the synthesis of functionalized fused dihydrofuran derivatives
("Figure Presented") An efficient aqueous oxidative cyclization mediated by the combination of iodosobenzene with tetra-(n-butyl)ammonium iodide provides a new convenient and useful route to functionalized fused dihydrofuran derivatives in moderate to excellent yields with high diastereoselectivities.
Ye, Yang,Wang, Linfei,Fan, Renhua
scheme or table
p. 1760 - 1763
(2010/05/01)

MhyADH catalysed Michael addition of water and in situ oxidation
The Michael addition of water is a major challenge. Here an enzymatic approach is described. Interestingly, the enzyme (MhyADH) does not only catalyse the Michael addition of water but also the in situ oxidation of the product.
Jin, Jianfeng,Oskam, Philip C.,Karmee, Sanjib K.,Straathof, Adrie J. J.,Hanefeld, Ulf
experimental part
p. 8588 - 8590
(2011/02/16)

Synthesis of chiloglottones - Semiochemicals from sexually deceptive orchids and their pollinators
A five-step synthesis of monoalkyl- and 2,5-dialkyl-1,3-cyclohexanediones (1) is described via a sequence involving sequential Birch reductions and alkylations from the readily accessible and inexpensive starting material, 3,5-dimethoxybenzoic acid. Two approaches were considered in which alkylation at C-2 occurs either prior or subsequent to the proposed reduction. The successful route, in which Birch reduction of a 3-alkyl resorcinol derivative (3) precedes alkylation was applied in the synthesis of chiloglottone 1 (1dc), in 58% overall yield. Chiloglottone 1 is a member of a new class of natural products, representing a known sex pheromone of the thynnine wasp Neozeleboria cryptoides and pollinator attractant in the Australian sexually deceptive orchid genus Chiloglottis. The synthetic homologues were assessed for their biological activity via electroantennographic detection.
Poldy, Jacqueline,Peakall, Rod,Barrow, Russell Allan
supporting information; experimental part
p. 4296 - 4300
(2009/12/06)

Raney ni-al alloy mediated hydrodehalogenation and aromatic ring hydrogenation of halogenated phenols in aqueous medium
Raney Ni-Al alloy in a dilute aqueous alkaline solution has been shown to be a very powerful reducing agent and is highly effective for the reductive dehalogenation of polyhalogenated phenols and aromatic ring hydrogenation of phenols to the corresponding cyclohexanols.
Liu, Guo-Bin,Zhao, Hong-Yun,Zhang, Jie,Thiemannb, Thies
experimental part
p. 342 - 344
(2010/01/16)

Cerium(IV) ammonium nitrate-catalyzed synthesis of β-keto enol ethers from cyclic β-diketones and their deprotection
A mild and efficient method for etherification of cyclic β-diketones with alcohols has been developed using a catalytic amount of cerium(IV) ammonium nitrate at room temperature to afford the corresponding β-keto enol ethers in good to excellent yields. The deprotections of enol ethers in water-acetonitrile (1:1) using a catalytic amount (10 mol %) of cerium(IV) ammonium nitrate have also been achieved. Copyright
Banerjee, Biplab,Mandal, Samir Kumar,Roy, Subhas Chandra
p. 16 - 17
(2007/10/03)

Photochemistry of 2-nitrobenzyl enol ethers: Oxidative C=C bond scission
(Chemical Equation Presented) 2-Nitrobenzyl enol ethers, when photolyzed in the presence of air, result in an oxidative C=C bond scission, forming a ketone as the major product (>60% yield). Enol release leads to the aldehyde as the minor product.
Yong, Promise K.,Banerjee, Anamitro
p. 2485 - 2487
(2007/10/03)

Fragmentation of tertiary cyclopropanol compounds catalyzed by vanadyl acetylacetonate
Tertiary cyclopropanol compounds react with a catalytic amount of vanadyl acetylacetonate in the presence of oxygen affording β-hydroxyketones and β-diketones. For 3-substituted-bicyclo[4.1.0]alkanols, peroxides are obtained, as are the β-hydroxyketones. Conversely, 2- ethoxycarbonylcyclopropyl silyl ethers produce ethyl γ-oxocarboxylate derivatives given the same reaction conditions.
Kirihara, Masayuki,Kakuda, Hiroko,Ichinose, Motohiro,Ochiai, Yuta,Takizawa, Shinobu,Mokuya, Asuka,Okubo, Kumiko,Hatano, Akihiko,Shiro, Motoo
p. 4831 - 4839
(2007/10/03)

Mild microwave-assisted hydrolysis of acetals under solvent-free conditions
Acetals are efficiently hydrolyzed with silica gel-supported pyridinium tosylate moistened with water in solvent-free conditions under microwave irradiation. The method is efficient and mild, with acid-sensitive 3-hydroxyacetals and 3-methoxyacetals being hydrolyzed in minutes in good yields.
He, Yanhong,Johansson, Martin,Sterner, Olov
p. 4153 - 4158
(2007/10/03)

Liquid phase oxidation of alkenes with nitrous oxide to carbonyl compounds
A variety of substrates including linear, cyclic, heterocyclic alkenes and their derivatives were tested in the liquid phase non-catalytic oxidation with nitrous oxide (N2O). The structure and composition of the alkenes have a significant effect on the reaction selectivity. With many alkenes, N 2O oxidation provides a selective way for the preparation of carbonyl compounds. The generation of carbene (or diazomethane) species is a remarkable feature of the oxidation of terminal alkenes.
Starokon,Dubkov,Babushkin,Parmon,Panov
p. 268 - 274
(2007/10/03)

Deoximation and dehydrazonation of ketoximes and ketophenylhydrazones by wet HMT in solid state under microwave conditions
A time and energy efficient process of generation of ketones from oximes and phenylhydrazones is reported under microwave irradiation utilising inexpensive and easily available reagent - hexamethylenetetramine under solvent-free condition with high yields.
Karchaudhuri, Nilay,De, Aparna,Mitra, Alok Kumar
p. 1537 - 1539
(2007/10/03)

Method for preparing chiral diphosphines
The invention concerns a method for preparing a compound of formula (1) wherein: A represents naphthyl or phenyl optionally substituted; and Ar1, Ar2independently represent a saturated or aromatic carbocyclic group, optionally substituted.
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(2008/06/13)

Allylic CH oxidation versus epoxidation of 2-cyclohexenols, catalyzed by chromium- and manganese-substituted polyoxometalates and salen complexes
2-Cyclohexenol (1) is oxidized chemoselectively to 2-cyclohexenone (2a) by the α-Keggin chromium-substituted polyoxometalate (POM) Ia as the catalyst and iodosobenzene as the oxygen source. For the chromium(salen) catalyst IIa the same chemoselectivity in favor of allylic CH oxidation is observed. The manganese-substituted POM Ib and the manganese(salen) complex IIb, however, afford appreciable amounts of the epoxy alcohol 2b. For the stereolabeled 5-tert-butyl-2-cyclohexenols 5, the diastereoselectivity of the epoxidation was appreciable (syn:anti 82:18) in the case of the manganese (salen) complex IIb with the cis isomer, while the manganese-substituted POM Ib exhibited no syn versus anti π-facial differentiation for the cis or trans diastereomer of the cyclohexenol 5. The observed syn hydroxy directivity for the manganese(salen) complex IIb is rationalized in terms of optimal hydrogen bonding between the MnV oxo complex IIb and the trans diastereomer of the allylic alcohol substrate 5. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany 2002.
Adam, Waldemar,Herold, Marike,Hill, Craig L.,Saha-Moeller, Chantu R.
p. 941 - 946
(2007/10/03)

Asymmetric hydrogenation method of a ketonic compound and derivative
The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
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(2008/06/13)

Process for the manufacture of 1, 3-cyclohexanedione
A new process for the manufacture of 1,3-cyclohexanedione is disclosed wherein a selected resorcinol is reduced with a hydrogen donor in the presence of a metal catalyst to produce a product which is then neutralized with an acid.
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(2008/06/13)

Tertiary cyclopropanol systems as synthetic intermediates: Novel ring-cleavage of tertiary cyclopropanol systems using vanadyl acetylacetonate
Tertiary cyclopropanol systems react with a catalytic amount of vanadyl acetylacetonate under an oxygen atmosphere to afford β-hydroxyketones and β-diketones.
Kirihara, Masayuki,Ichinose, Motohiro,Takizawa, Shinobu,Momose, Takefumi
p. 1691 - 1692
(2007/10/03)

Chiral acetals in organic synthesis: Regioselective synthesis of 2-and 3-hydroxy acetals from 2,3-olefinic acetals. Reinvestigation and further applications
Achiral as well as chiral 2,3-olefinic acetals are converted into 2- and 3- hydroxy acetals via LAH reduction of the corresponding epoxides and via bromohydrins followed by TBTH reductions respectively. Synthesis of 1,3-diones is described. Compounds from chiral systems are further utilized for asymmetric synthesis.
Vankar, Yashwant D.,Reddy, M. Venkatram,Chaudhuri, Narayan C.
p. 11057 - 11078
(2007/10/02)

Inhibitors of the advanced glycosylation of proteins and methods of use therefor
The present invention relates to compositions and methods for inhibiting nonenzymatic cross-linking (protein aging). Accordingly, a composition is disclosed which comprises an agent capable of inhibiting the formation of advanced glycosylation endproducts of target proteins by reacting with a carbonyl moiety of an early glycosylation product of such target proteins resulting from their initial glycosylation. The method comprises contacting the target protein with the composition. Both industrial and therapeutic applications for the invention are envisioned, as food spoilage and animal protein aging can be treated.
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(2008/06/13)

Radical Cyclization of Epoxyketones via a 1,5-Bun3Sn Group or a 1,5-H Atom Transfer
Radical cyclization of epoxyketones is initited by Bun3Sn radical addition to epoxyketones, followed by epoxide fragmentation, 1,5-H- or 1,5-Bun3Sn transfer, and cyclization.
Kim, Sunggak,Koh, Jae Suk
p. 1377 - 1378
(2007/10/02)

Method of preparing 2-acylresorcinols
A method of preparing a 2-acylresorcinol which comprises dehydrogenating a 2-acyl-1,3-cyclohexanedione of the general formula wherein R1 represents an alkyl, aralkyl or aryl group, and RZrepresents hydrogen, or an alkyl, alkoxy or acylamino group, in the presence of a dehydrogenation catalyst (such as a Group VIII metal) or a dehydrogenation agent (such as sulphur or selenium) at an elevated temperature, to provide a 2-acylresorcinol of the general formula wherein R1 and R2 are as defined.
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(2008/06/13)

Synthesis of cylcic ketones by activated nitriles
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Fadda,El-Houssini
p. 915 - 917
(2007/10/02)

Mechanism of hydrolysis and structure-stability relationship of enaminones as potential prodrugs of model primary amines
The objective of this work was to investigate the chemistry and the structure-stability relationship of enaminones (a class of enamines formed between a primary amine and a 1,3-dicarbonyl compound) and to evaluate their potential usefulness as prodrugs of primary amines. The acid-catalyzed degradation of the enaminones was found to be very sensitive to minor differences in the structure of the 1,3-dicarbonyl compound used to form the enaminone, but relatively insensitive to changes in the amine portion of the enaminones. A correlation was found between the rate of enaminone hydrolysis and the pK(a) of the 1,3-dicarbonyl compound, suggesting that the rate-controlling step in the hydrolysis of the enaminones was the proton addition to the vinyl carbon of the enaminone. Enaminones formed with cyclic 1,3-dicarbonyl compounds were significantly more stable than those formed with structurally similar acyclic compounds. Based on chemical stability considerations alone, enaminones do not appear to be good candidates as prodrugs of primary amines. Evidence is presented, however, that enaminones formed between amines and 1,3-ketoesters or lactones may be subject to enzyme-catalyzed degradation. Further research on the design of enaminones destabilized by a triggering enzymatic event that results in the loss of conjugation (e.g., ester or lactone hydrolysis or an oxidation/reduction event) may prove worth pursuing.
Naringrekar,Stella
p. 138 - 146
(2007/10/02)

Process for manufacture of resorcinol
A process for the manufacture of resorcinol is described which relies upon the intermediacy of a α,β-unsaturated ketone which can be reacted with a hydroxy moiety-containing compound to obtain a resorcinol precursor which is subsequently converted to resorcinol. In a specific embodiment, 2-cyclohexenone is reacted dehydrogenated to resorcinol. In antoher embodiment, 2-cyclohexenone is oxidized to cyclohexane-1,3-dione which is dehydragenated obtain resorcinol.
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(2008/06/13)

Preparation, Reactivity, and Spectral Properties of 1,3-Dioxin Vinylogous Esters: Versatile β-Ketovinyl Cation Equivalents
A full account of the preparation, reactivity, and spectral properties of three 1,3-dioxin vinylogous esters (4-6) is presented.The synthetic approach of these versatile β-ketovinyl cation equivalents involves a BF3*Et2O-promoted Prins reaction between cyclic 1,3-diketones (i.e., 1,3-cyclopentanedione, 1,3-cyclohexanedione, and 1,3-cycloheptanedione) and either formaldehyde or trioxane.The reactions explored include reductive and alkylative 1,3-ketone transpositions, affording a variety of simple β-unsubstituted and β-substituted α-hydroxymethyl α,β-enones, alkylations with carbon electrophiles, and hydroxylations with oxygen electrophiles.
Smith, Amos B.,Dorsey, Bruce D.,Ohba, Masashi,Lupo, Andrew T.,Malamas, Michael S.
p. 4314 - 4325
(2007/10/02)

Palladium(0)-catalyzed isomerization of α,β-epoxy ketones to β-diketones
In the presence of catalytic amounts of tetrakis(triphenylphosphine)palladium(0) and 1,2-bis(diphenylphosphino)ethane, α,β-epoxy ketones isomerize to the corresponding β-diketones in high yields.Both open-chain and cyclic substrates can be used.Possible reaction mechanisms are discussed.
Suzuki, M.,Watanabe, A.,Noyori, R.
p. 230 - 236
(2007/10/02)

REGIOSELECTIVE REDUCTIONS OF 2,3-EPOXY ACETALS WITH ZINC-CHLOROTRIMETHYLSILANE AND LITHIUM ALUMINIUM HYDRIDE: CONVENIENT SYNTHESIS OF 1,2 AND 1,3-DIONES
A variety of 2,3-epoxy acetals have been found to undergo regioselective reductions with zinc-chlorotrimethylsilane and lithium aluminium hydride to give 2-hydroxy and 3-hydroxy acetals respectively.Their oxidation followed by hydrolysis furnished the corresponding 1,2- and 1,3-diones in good yields.
Vankar, Yashwant D.,Chaudhuri, Narayan C.,Rao, C. Trinadha
p. 551 - 554
(2007/10/02)

Cyclohexane-1,3-dione derivatives
Cyclohexane-1,3-dione derivatives of the formula I STR1 where R1 is cycloalkyl of 3 to 12 carbon atoms which may or may not be olefinically monounsaturated to tetraunsaturated, can be substituted by not more than 3 methyl or ethyl groups, one vinyl, methylvinyl or allyl group, 1 or 2 chlorine atoms or one alkoxy group of 1 to 4 carbon atoms and can be bridged by an alkylene chain of not more than 4 carbon atoms, X is alkylene of 1 to 5 carbon atoms, which can be monounsaturated or diunsaturated, interrupted by not more than 2 sulfur or oxygen atoms and substituted by not more than 3 alkyl groups of 1 to 3 carbon atoms, R2 is hydrogen of alkoxycarbonyl where alkoxy is of 1 to 2 carbon atoms, R3 is alkyl of 1 to 4 carbon atoms, R4 is alkyl of 1 to 3 carbon atoms, alkenyl of 3 or 4 carbon atoms, propargyl or haloalkenyl of 3 or 4 carbon atoms and 1 to 3 halogen atoms, and the salts of these compounds, processes for their preparation, herbicides containing these compounds, and their use.
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(2008/06/13)

A Method for Mild Photochemical Oxidation; Conversion of Phenacyl Sulfides into Carbonyl Compounds
Sunlamp irradiation of phenacyl sulfides PhCOCH2SCHRR' affords thiocarbonyl compounds S=CRR' that can be trapped in high yield by using the nitronate CH3CH=N+(OTBS)O-; the heterocycle 3 resulting from 1,3-dipolar cycloaddition is cleaved rapidly by fluoride ion to give ketones or aldehydes.
Vedejs, E.,Perry, D. A.
p. 573 - 575
(2007/10/02)

A CONVENIENT SYNTHESIS OF CYCLOHEPTANE-1,3-DIONE
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Bhushan, Vidya,Chandrasekaran, S.
p. 339 - 346
(2007/10/02)

REACTION OF 2-ACETYL-2-CYCLOALKEN-1-ONES WITH CYCLIC β-DIKETONES
The corresponding 2-acetyl-1,3-cyclohexadien-1-ols were obtained by the reduction of 2-acetyl-3-chloro-2-cyclohexen-1-one and 2-acetyl-3-chloro-5,5-dimethyl-2-cyclohexen-1-one with zinc activated by silver acetate.They were studied in the Michael addition reaction with dimedone and 1,3-cyclohexanedione in the presence of sodium methoxide.It was concluded that the transformation of these 2-acetyl-2-cyclohexen-1-ones into the corresponding 2-acetyl-1,3-cyclohexadien-1-ols is reversible.By dehydration of the Michael addition adducts and reaction with ammonia tricycliccompounds with an additional pyran or dihydropyridine ring were obtained.
Akhrem, A. A.,Lakhvich, F. A.,Pyrko, A. N.
p. 2027 - 2033
(2007/10/02)

Process for the preparation of cyclohexane-1,3-dione from δ-ketohexanoic acid ester
Cyclohexane-1,3-diones are prepared by passing δ-ketocarboxylic acid esters in the gaseous phase over a temperature of from 250° C. to 500° C. at a catalyst. The catalyst contains at least one element of groups III B or IV B of the Periodic System in the form of a compound. Particularly preferred catalysts are thorium compounds on charcoal carriers.
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(2008/06/13)

Liquid phase ammoxidation of cyclohexanone and/or cyclohexanol
Cyclohexanone and/or cyclohexanol can be ammoxidized in the liquid phase to heterocyclic compounds by contacting the cyclohexanone and/or cyclohexanol with various oxidation catalysts in the presence of molecular oxygen and ammonia.
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(2008/06/13)

SYNTHESIS AND PROPERTIES OF 2-DIAZO-1,3-DICARBONYL COMPOUNDS. V. SYNTHESIS AND 1,2-NUCLEOPHILIC REARRANGEMENTS OF SOME 2-DIAZO-3-HYDROXY-1-CYCLOHEXANONES
2-Diazo-3-hydroxy, 2-diazo-3-hydroxy-5,5-dimethyl, and 2-diazo-3-hydroxy-4,4,6,6-tetramethyl-1-cyclohexanones were obtained by reduction of 2-diazo 1,3-diketones of the cyclohexane series, and their spectral characteristics were determined.Photolytic, catalytic, and thermal elimination of nitrogen in these diazo compounds is only accompanied by 1,2-nucleophilic rearrangements.During photolysis of the diazohydroxycyclohexanones in an aqueous medium the main reaction path is a Wolff rearrangement, i.e., ring contraction with the formation of hydroxy and unsaturated acids of the cyclopentane series and some of their derivatives.Acid decomposition of the diazohydroxycyclohexanones leads mainly to an alkyl shift as a result of which (hydroxymethylene)cyclopentanones are formed with ring contraction.
Nikolaev, V. A.,Zhdanova, O. V.,Korobitsyna, I. K.
p. 488 - 498
(2007/10/02)

Vapor phase catalytic oxidation and/or ammoxidation of cyclohexanone and/or cyclohexanol to phenol and/or aniline
Cyclohexanone and/or cyclohexanol can be oxidized in the vapor phase to phenol by contacting the cyclohexanone and/or cyclohexanol with a suitable oxidation catalyst in the presence of molecular oxygen. Suitable catalysts are solids comprising Mo, W, Sb and/or V oxides or complexes thereof. The catalysts may be promoted with additional elements.
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(2008/06/13)

Reduction of β-Arylthio- or β-Alkylthio-αβ-Unsaturated Ketones
The preparation and reduction of β-arylthio or β-alkylthio-αβ-unsaturated ketones (1) with lithium aluminium hydride or sodium borohydride have been examined.Reduction of the ketones (1) with lithium aluminium hydride gave αβ-unsaturated ketones (2), in which the olefinic (R1) and carbonyl (R2) substituents are reversed compared with the starting αβ-unsaturated ketone (1), or the saturated γ-hydroxy-sulphides (3).Reduction of the ketones (1) with sodium borohydride afforded only the αβ-unsaturated ketones (2).Reduction of (1) with sodium borohydride in the presence of metal halides gave the saturated ketones (5).
Nishio, Takehiko,Omote, Yoshimori
p. 934 - 938
(2007/10/02)