- Water-promoted surface basicity in FeO(OH) for the synthesis of pseudoionones (PS) and their analogues
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Use of Iron oxyhydroxide (γ-FeO(OH)) as a robust catalyst for the synthesis of important intermediates like pseudoionones and their analogues through the C-C bond formation reactions like knoevenagel and aldol condensation is explored. These motifs are the building blocks for the construction of the sesquiterpenes as well as the diterpenes such as retinoic acid, Vitamin A etc. Iron oxyhydroxide (γ-FeO(OH)) was synthesized and well characterized using XRD, FT-IR, TEM, XPS and adsorption studies to establish the catalytic activity. A thorough investigation on the nature of basic sites and the role of water as a promoter was explored based on dye adsorption, in situ methanol dissociation and CO2 adsorption studies. The catalyst also showed a wide range of substrate scope with active methylene groups involving various functional groups such as cyanides, esters and acetophenones along with its stability and reproducibility.
- Vernekar, Dnyanesh,Sakate, Sachin S.,Rode, Chandrashekhar V.,Jagadeesan, Dinesh
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Read Online
- Nanoplatelet-based reconstructed hydrotalcites: Towards more efficient solid base catalysts in aldol condensations
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Rehydration of Mg-Al hydrotalcite in the liquid phase using ultrasounds or a high stirring speed leads to nanoplatelets with surface areas of 400 m 2 g-1, displaying catalytic activities in aldol condensations up to 8 times higher than the best catalytic system reported in the literature. The Royal Society of Chemistry 2005.
- Abello,Medina,Tichit,Perez-Ramirez,Cesteros,Salagre,Sueiras
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Read Online
- KF on γ-alumina: An efficient catalyst for the aldol condensation to pseudoionones
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KF/γ-alumina is an effective catalyst for the aldol condensation of citral with acetone. Even at a relatively low acetone/citral ratio of 1-10, the selectivity to pseudoionones was high, ranging between 82% and 97%. X-ray diffraction shows the presence of KF and K3AlF6 crystallographic phases on the supported catalyst. At KF loadings of 3-6.75 mmol g-1, a pretreatment of the catalyst by heating to 450 °C was necessary to obtain an active catalyst. However, samples with KF loadings of 8.5 mmol g-1 and higher were active even without pretreatment, facilitating handling and use of the catalysts. The development of (1 1 1) planes revealed by in situ XRD during the thermal activation process correlates with the activity for aldol condensation.
- Raju, Vadikukarasi,Radhakrishnan, Rajitha,Jaenicke, Stephan,Chuah, Gaik Khuan
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Read Online
- Epoxides from myrcene: New versatile tools for the synthesis of functionalized acyclic terpenoids
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Mono-epoxides prepared from myrcene, were used as synthetic intermediates to obtain citral, linalool, geranylacetone and pseudo-ionone.
- Fauchet,Miguel, B. Arreguy-San,Taran,Delmond
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Read Online
- Increasing the basicity and catalytic activity of hydrotalcites by different synthesis procedures
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Hydrotalcites have been synthesized by three different procedures: conventional precipitation-aging, aging under microwave irradiation, and sonication during the coprecipitation step. The synthesis procedure has an effect on the crystal size and textural properties of the hydrotalcite (HT) and the Al2O3-MgO mixed oxides formed upon calcination. HT samples prepared under sonication at 298 K are formed by dispersed and homogenous particles of 80-nm average particle size. They also produce upon calcinations the mixed oxides with the largest surface area (~300 m 2g-1). This method of preparation increases not only the surface area but also the number of defects in the solid, leading to sites of higher basicity. This was determined by means of catalytic reactions such as Knoevenagel and aldol condensations which demand basic sites of different strengths. Hydrotalcites were regenerated from mixed oxides by hydration while giving Broensted basic sites. Samples originally prepared by sonication present smaller crystallite size and have a larger number of accessible active sites. With these samples acetone/citral condensations with 96 and 99% conversion and selectivity, respectively, are achieved in a 15-min reaction time.
- Climent,Corma,Iborra,Epping,Velty
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Read Online
- Preparation method of pseudoionone
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The invention provides a preparation method of a vitamin A intermediate pseudoionone. The method relates to a reaction for preparing pseudoionone by catalyzing condensation of acetone and citral by using a novel catalyst, the use amount of reaction acetone can be effectively reduced by using the novel catalyst, self-polymerization and copolymerization of citral and pseudoionone in the reaction arereduced, and the reaction selectivity and yield are improved.
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Paragraph 0027-0056
(2021/03/13)
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- Continuous synthesis method of pseudoionone
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The invention belongs to the field of pseudoionone preparation, and relates to a continuous synthesis method of pseudoionone, which comprises the following steps: continuously introducing citral, acetone and an alkaline catalyst containing inorganic alkali and acetate into a tubular reactor to carry out Aldol condensation reaction, and gradually raising the reaction temperature of the tubular reactor, and continuously introducing the condensation reaction product into a multi-kettle series acetone recovery device to recover acetone, carrying out extraction layering on the acetone removal product, and neutralizing the obtained oil layer with dilute acid to obtain the pseudoionone. On the premise of economy and environmental protection, high yield and high purity of pseudoionone and high conversion rate of citral serving as a raw material are realized, acetone and an alkaline water layer are recycled, and the production cost is reduced.
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Paragraph 0035-0084
(2021/04/10)
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- PROCESS OF MAKING PSEUDOIONONE AND HYDROXY PSEUDOIONONE IN AQUEOUS MIXTURES COMPRISING CITRAL AND ACETONE, COMPRISING ADDING FIRST AND SECOND AMOUNTS OF HYDROXIDE
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Described is a process of making pseudoionone and hydroxy pseudoionone comprising the steps of (i) preparing a first aqueous mixture comprising first concentrations of acetone, citral and hydroxide, (ii) producing a second aqueous mixture by allowing to react for a reaction time the components of the first aqueous mixture and (iii) producing a third aqueous mixture by adding to the second aqueous mixture a second amount of hydroxide so that an additional amount of pseudoionone is formed in the third aqueous mixture. The invention further suggests an apparatus for making pseudoionone and hydroxy pseudoionone as well as to a respective process and use of said apparatus in making pseudoionone and hydroxy pseudoionone.
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Page/Page column 30-33
(2020/06/05)
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- APPARATUS FOR AND PROCESS OF MAKING PSEUDOIONONE AND HYDROXY PSEUDOIONONE
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The invention relates to an apparatus (1) for producing pseudoionone and hydroxy pseudoionone. It suggests an apparatus (1) comprising first and second substantially vertically oriented reactor chambers oriented such that components flow through the first and second reactor chambers in different directions, wherein the first reactor chamber (13) is configured to receive a first component feed (C1) containing a first aqueous mixture through an inlet (15), and to produce a second aqueous mixture, and wherein the apparatus (1) comprises a mixing device (17) positioned downstream of the first component feed inlet (15)and configured to add a second component feed (C2) to the first component feed (C1) when the second aqueous mixture has formed, and the second reactor chamber (23) is configured to receive the first and second component feeds unified in the mixing device (17) from the first reactor chamber (13) and to produce a third aqueous mixture from the first and second aqueous mixtures. The invention further suggests a method and a use for producing pseudoionone and hydroxy pseudoionone.
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Page/Page column 29-31
(2020/06/05)
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- Method for catalytically synthesizing pseudoionone by using alkaline immobilized ionic liquid
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The invention discloses a method for catalytically synthesizing pseudoionone by using alkaline immobilized ionic liquid. In the method, citral is adopted as a raw material, acetone is slowly dropwiseadded at 40-50 DEG C under the condition that the alkaline immobilized ionic liquid is used as a catalyst to react, thereby obtaining the pseudoionone; a carrier used in the alkaline immobilized ionicliquid is a PS material, the PS material is polystyrene, and the alkaline immobilized ionic liquid is one of the following components shown in the specification. The alkaline immobilized ionic liquidcatalyst disclosed by the invention is easy to separate from a reaction solution, avoids the condition of catalyst loss caused by multiple cyclic reactions, and has the advantages of high product yield, clean product and the like in the process of synthesizing pseudoionone.
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Paragraph 0023-0033
(2020/06/09)
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- Method for synthesizing alpha,gamma-unsaturated dienone from propargyl alcohol and catalyst system used for method
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The invention discloses a method for synthesizing alpha,gamma-unsaturated dienone from propargyl alcohol and a catalyst system used for the method. The method comprises the following steps: (1) a Saucy-Marbet reaction is carried out on propargyl alcohol and alkoxy propylene under the action of an acidic resin catalyst to obtain an allenyl ketone intermediate; and (2) a heterogeneous reaction is carried out on the allenyl ketone under the action of a solid base catalyst to obtain the alpha,gamma-unsaturated dienone product. The method disclosed by the invention has the main advantages that solid catalysts are adopted in the two steps of reactions, the catalyst activity is high, and the catalysts are easy to separate from products. Compared with a separation process in an existing homogeneous acid catalysis process, the separation process in the method provided by the invention is greatly simplified. Secondly, the acid resin catalyst and solid base catalyst adopted in the method both canbe continuously recycled, so that the cost is low, and the method is economical and feasible and is superior to the existing known process.
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Paragraph 0055-0057; 0059-0060
(2019/04/10)
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- A pseudo-Ionone synthesis method (by machine translation)
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The invention relates to a pseudo-Ionone synthetic method, include a dehydrogenation-Linalool with 2 - methoxy propylene in a microchannel reactor Saucy - Marbet sequentially and isomerization reaction preparation of pseudo-Ionone. In a microchannel reactor dehydrolinalool through Saucy - Marbet reaction and the isomerization reaction to make the pseudo-Ionone, realizes the continuous production of pseudo-Ionone, and high efficiency, less reaction steps, high yield, high selectivity, and less pollution, accord with the green chemical development concept. (by machine translation)
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Paragraph 0038
(2018/10/27)
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- Methylionone and preparation method of methylionone intermediate
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The invention discloses methylionone and a preparation method of a methylionone intermediate. According to an existing preparation method of methylionone, a lot of alkali usually needs to be wasted, and on the other hand, a lot of three wastes are caused. Under the conditions that citral and butanone serve as raw materials, PEG serves as a solvent and metal hydroxide serves as a condensation agent, an Aldol condensation reaction is conducted, and false methylionone is synthesized; the obtained false methylionone is subjected to a cyclization reaction catalyzed by acid, and methylionone is synthesized. According to methylionone and the preparation method of the methylionone intermediate, an adopted PEG-M(OH)x catalysis system improves the synthesis efficiency of the false methylionone, and the ratio of the false methylionone is kept at 68-79%; moreover, an adopted phosphoric acid-normal hexane catalytic cyclization system greatly improves the cyclization yield; an adopted catalytic condensation system can be used indiscriminately for several times, so that the cost is reduced, and environmental pollution is also reduced.
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Paragraph 0030; 0031; 0032; 0033; 0034-0037; 0045-0046
(2017/08/29)
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- Synthesis of apo-13- and apo-15-lycopenoids, cleavage products of lycopene that are retinoic acid antagonists
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Consumption of the tomato carotenoid, lycopene, has been associated with favorable health benefits. Some of lycopene's biological activity may be due to metabolites resulting from cleavage of the lycopene molecule. Because of their structural similarity to the retinoic acid receptor (RAR) antagonist, β-apo-13-carotenone, the "first half" putative oxidative cleavage products of the symmetrical lycopene have been synthesized. All transformations proceed in moderate to good yield and some with high stereochemical integrity allowing ready access to these otherwise difficult to obtain terpenoids. In particular, the methods described allow ready access to the trans isomers of citral (geranial) and pseudoionone, important flavor and fragrance compounds that are not readily available isomerically pure and are building blocks for many of the longer apolycopenoids. In addition, all of the apo-11, apo-13, and apo-15 lycopenals/lycopenones/lycopenoic acids have been prepared. These compounds have been evaluated for their effect on RAR-induced genes in cultured hepatoma cells and, much like β-apo-13-carotenone, the comparable apo-13-lycopenone and the apo-15-lycopenal behave as RAR antagonists. Furthermore, molecular modeling studies demonstrate that the apo-13-lycopenone efficiently docked into the ligand binding site of RARα. Finally, isothermal titration calorimetry studies reveal that apo-13-lycopenone acts as an antagonist of RAR by inhibiting coactivator recruitment to the receptor.
- Narayanasamy, Sureshbabu,Sun, Jian,Pavlovicz, Ryan E.,Eroglu, Abdulkerim,Rush, Cassandra E.,Sunkel, Benjamin D.,Li, Chenglong,Harrison, Earl H.,Curley, Robert W.
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p. 1021 - 1029
(2017/05/17)
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- Aldol Condensations Catalyzed by Basic Anion-Exchange Resins
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The aldol condensations of various aldehydes with ketones in the presence of anionic (basic) ion-exchange resins have been investigated. Both batch and continuous modes were studied and compared for the reaction of citral (a mixture of geranial and neral) with acetone to give ψ-ionone. Different reaction conditions were investigated, and the performances of five different ion-exchange resins were compared. The most stable resins could be used for 10 cycles in batch mode or 1000 min in continuous mode without a significant loss in activity or selectivity.
- Bonrath, Werner,Pressel, Yann,Schütz, Jan,Ferfecki, Erich,Topp, Klaus-Dieter
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p. 3584 - 3591
(2016/12/14)
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- Process for preparing pseudoionone
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Use of pure lanthanum oxide which is obtained by calcination of oxygen-containing lanthanum salts at temperatures of at least 700° C. as heterogeneous catalyst in the aldol condensation of citral and acetone to give pseudoionone, and process for the preparation of pseudoionone by aldol condensation of citral and acetone in the liquid phase using pure lanthanum oxide.
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Page/Page column 5
(2015/01/07)
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- Alanine-supported protic ionic liquids as efficient catalysts for aldol condensation reactions
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A series of novel protic ionic liquids were immobilized on alanine, a cheap readily available amino acid. These short aliphatic chain ionic liquids have a low cost of preparation, a low toxicity, and need simple synthesis/purification processes. Their catalytic activity was tested for citral-acetone and benzaldehyde-acetone condensations, two reactions with an interest for pharmacological as well as flavor and fragrance industry. Good results were obtained in terms of conversion and selectivity; moreover, the catalysts can be recycled and reused for several consecutive cycles without significant loss of activity.
- Cota, Iuliana,Medina, Francesc,Gonzalez-Olmos, Rafael,Iglesias, Miguel
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- (6R,10R)-6,10,14-TRIMETYLPENTADECAN-2-ONE PREPARED FROM 6,10-DIMETYLUNDECA-3,5,9-TRIEN-2-ONE
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The present invention relates to a process of manufacturing (6R,10R) -6,10,14-trimethylpentadecan-2-one in a multistep synthesis from 6,10- dimethylundeca-3,5,9-trien-2-one. The process is very advantageous in that it forms in an efficient way the desired chiral product from a mixture of stereoisomers of the starting product.
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Page/Page column 37; 38
(2014/07/08)
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- 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) an efficient homogeneous catalyst for aldol condensation reactions. Study of the catalyst recovery and reusability using CO2
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In this work it was shown that TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene), a cheap and commercially available guanidine base, efficiently catalyzes aldol condensation reactions yielding interesting products for pharmacological and fragrance industries. This methodology works under solvent-less conditions and affords with very good conversions the corresponding products. Moreover, a simple and effective separation protocol using the CO2 fixation was employed. The catalyst could be recovered and re-used for three consecutive runs without significant loss of activity.
- Cota, Iuliana,Medina, Francisco,Sueiras, Jesús E.,Tichit, Didier
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experimental part
p. 385 - 387
(2011/02/28)
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- Aldol condensation reaction and catalyst therefore
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The invention relates to a novel processes for cross aldol reactions using strongly basic, anionic, macroreticular polymeric resin with quaternary ammonium groups of the type -CH2N+(CH3)3 as heterogeneous catalysts. This catalyst is recyclable and the process can be repeated several times.
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Page/Page column 6
(2009/01/20)
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- ALDOL CONDENSATION
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The invention relates to a novel processes for producing ketones, and more specifically, to processes for producing unsaturated ketones using Ca/Na on silica as solid base supported catalysts. This process results in yields and greater selectivity for the target products, while allowing the recycling of the catalyst.
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Page/Page column 5; 8; 9
(2008/12/07)
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- Gold-catalyzed cycloisomerization of cyclopropyl alkynyl acetates: A versatile approach to 5-, 6-, and 7-membered carbocycles
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Nonclassical chirality transfer? Depending on the substitution pattern of propargyl acetates, a gold-catalyzed homologous Rautenstrauch reaction generates either 5- or 6-membered ring systems (see scheme). The stabilization of cationic intermediates is crucial for this reaction to succeed. The underlying principle for the good chirality transfer observed could be gold-stabilized nonclassical carbocations having configurational stability.
- Zou, Yue,Garayalde, David,Wang, Quanrui,Nevado, Cristina,Goeke, Andreas,Ito, Yoshihiko
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supporting information; experimental part
p. 10110 - 10113
(2009/05/30)
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- One-pot selective oxidation/olefination of primary alcohols using TEMPO-BAIB system and stabilized phosphorus ylides
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A one-pot process for the synthesis of α,β-unsaturated esters from a variety of alcohols, obtained in good yields and diastereoselectivities, is described. The use of BAIB/TEMPO system at the oxidizing step authorizes the chemoselective homologation of primary alcohols in the presence of secondary ones.
- Vatèle, Jean-Michel
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p. 715 - 718
(2007/10/03)
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- METHOD FOR THE PRODUCTION OF TETRAHYDROGERANYLACETONE
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The invention relates to a method for the production of tetrahydrogeranylacetone (tetrahydropseudoionone) by means of aldolcondensation of citral with acetone and subsequent hydrogenation. The invention also relates to the utilization of the tetrahydrogeranylacetone thus obtained for the production of phytol, isophytol, tocopherol and/or tocopherol derivatives. The invention further relates to methods for the production of tocopherols and/or tocopherol derivatives.
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Page/Page column 12; 13
(2008/06/13)
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- Aldol condensations over reconstructed Mg-Al hydrotalcites: Structure-activity relationships related to the rehydration method
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Two different rehydration procedures in the liquid or gas phase have been applied to reconstruct mixed oxides derived from calcined hydrotalcite-like materials to be used as catalysts for aldol condensation reactions. The as-synthesized hydrotalcite, its decomposition product, as well as the reconstructed solids upon rehydration were characterized by XRD, N2 adsorption, He pycnometry, FTIR, SEM, TEM, 27Al MAS-NMR and CO 2-TPD (TPD = temperature-programmed desorption). Compared to the Mg-Al mixed oxide rehydrated in the gas phase (HT-rg), that rehydrated in the liquid phase (HT-r1) exhibits a superior catalytic performance with respect to the aldol condensation of citral with ketones to yield pseudoionones and in the self-aldolization of acetone. The textural properties of HT-r1 and HT-rg differ strongly and determine the catalytic behavior. A memory effect led to a higher degree of reconstruction of the lamellar structure when the mixed oxide was rehydrated in the gas phase rather than in the liquid phase, although liquid-phase rehydration under fast stirring produced a surface area that was 26 times greater. This contrasts to typical statements in the literature claiming a higher degree of reconstruction in the presence of large amounts of water in the medium. CO2-TPD shows that the number of OH- groups and their nature are very similar in HT-rg and HT-r1, and cannot explain the markedly different catalytic behavior. Accordingly, only a small fraction of the available basic sites in the rehydrated samples is active in liquid-phase aldol condensations. Our results support the model in which only basic sites near the edges of the hydrotalcite platelets are partaking in aldol reactions. Based on this, reconstructed materials with small crystallites (produced by exfoliation during mechanical stirring), that is, possessing a high external surface area, are beneficial in the reactions compared to larger crystals with a high degree of intraplatelet porosity.
- Abello, Sonia,Medina, Francesc,Tichit, Didier,Perez-Ramirez, Javier,Groen, Johan C.,Sueiras, Jesus E.,Salagre, Pilar,Cesteros, Yolanda
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p. 728 - 739
(2007/10/03)
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- Heterogeneously catalyzed reactive distillation in the suspension mode
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Process for carrying out a reactive distillation in the presence of a heterogeneous catalyst which is suspended as disperse phase in the liquid, wherein part of the catalyst-containing suspension is continuously discharged from the column and is treated in a work-up stage and at least part of the work-up catalyst is returned to the column.
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- CONTINUOUS METHOD FOR THE PRODUCTION OF CARBONYL COMPOUNDS
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The invention relates to a method for the continuous production of higher-chained carbonyl compounds by reacting lower-chained carbonyl compounds with aldehydes on basic or acidic catalysts in a rectification column.
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Page/Page column 16-17
(2008/06/13)
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- CONTINUOUS PROCESS FOR PRODUCING PSEUDOIONONES AND IONONES
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The invention relates to a continuous process for producing pseudoionones of general formulas (I) and (I′) as well as isomers thereof, whereby: R1represents CH3 or (a); R2 and R3 represent hydrogen, CH3 or C2H5, and; R4 and R5represent hydrogen or CH3. These pseudoionones are produced by reacting an aldehyde of formula (II) with an excess of a ketone of general formula (III), whereby R1, R2 and R3 have the aforementioned meanings, in the presence of water and alkali hydroxide at an increased temperature and in a homogeneous solution. The inventive process is characterized in that: a) the intermixing of the homogeneous solution consisting of aldehyde, ketone and aqueous alkali lye occurs at a temperature ranging from 10 to 120 °C; b) the undissolved water and alkali hydroxide contained in the reaction mixture are subsequently separated out; c) while avoiding back mixing, the homogeneous reaction mixture is then guided through a reactor, which permits a residence time ranging from 2 to 300 minutes, at a temperature that is 10 to 120 °C higher than the boiling point of the lowest-boiling component and under a vapor pressure p ranging from 106 to 107 Pa; d) the reaction mixture is cooled by expansion; e) ketone is removed from the reaction mixture using vapor flowing in the opposite direction and; f) the raw product is dried and rid from excessive aldehyde and secondary components via a rectification column.
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Page/Page column 8
(2008/06/13)
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- New access to pseudo-ionones and pseudo-iso-methyl ionones from geranyl derivatives
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Pseudo-ionones and pseudo-iso-methyl ionones, precursors of fragrant derivatives were obtained from geranyl chloride, an industrially available starting material.
- Boulin,Arreguy-San Miguel,Delmond
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p. 1047 - 1055
(2007/10/03)
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- Process for the preparation of unsaturated 4,5-allene ketones, 3,5-diene ketones and the corresponding saturated ketones
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Process for the preparation of unsaturated 4,5-allene ketones by reaction of tertiary propargyl alcohols with alkenyl alkyl ethers or ketals in the presence of aliphatic sulfonic acids or sulfonic acid salts.
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- Synthesis of sesquiterpene polyene hydroperoxides by regio- and stereoselective transposition reactions
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Isomeric unsaturated alcohols (8), (16), (18) and (20), on exposure to hydrogen peroxide or water in the presence of an acid catalyst, undergo exceptionally regio- and stereoselective substitution reactions to form hydroperoxide (3) and alcohol (8) respectively. E/Z isomeric ratios of transposition products indicate that the intermediate acyclic carbocations (21) and (22) are not interconverting under the reaction conditions. Practical syntheses of α-farnesene autoxidation products have been developed based on these transposition reactions.
- Fielder, Simon,Rowan, Daryl D.,Sherburn, Michael S.
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p. 12907 - 12922
(2007/10/03)
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- Photochemical transformations of terpenoids in the presence of cyclodextrins
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The effect of complexation of terpene compounds with cyclodextrins on photolysis depends on the type of cyclodextrin and on the structure of the initial substrates. In some cases, only a change in the reaction rate is observed; in other cases, the complexation results in allylic rearrangements, hydride and acyl shifts, and cyclization with the formation of four-, five-, and six-membered cycles, whereas only cis-trans isomerization reactions are observed in the absence of complexation.
- Luzina,Tatarova,Korchagina,Salakhutdinov,Barkhash
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p. 183 - 193
(2007/10/03)
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- Efficient synthesis of pseudoionone by oxidative decarboxylation of allyl β-ketoesters
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The palladium catalyzed oxidative decarboxylation of allyl β-ketoesters is used, in mild conditions, to synthesize efficiently pseudoionone from technical grade myrcene.
- Mercier,Mignani,Aufrand,Allmang
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p. 1433 - 1436
(2007/10/02)
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- Synthesis of Allenes by 1,6-Addition of Organocuprates to Polarized Enynes
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Ten β-allenic esters, ketones, and thioesters 15 bearing alkyl, alkenyl, aryl, and trimethylsilyl groups are synthesized in 57-85percent yield by 1,6-addition of organocuprates to polarized enynes 10.The dependence of the regioselectivity of the protonation of the allenyl enolate intermediate 7 on the protonating agent is studied; pure allenes are obtained by quenching the intermediate with pivalic acid at -80 deg C.The method is applied in a short synthesis of pseudoionone (18).
- Krause, Norbert
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p. 2173 - 2180
(2007/10/02)
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- The Stereoselective Synthesis of α,β-Unsaturated Ketones by the Stepwise Cross-Coupling Reaction of -(2-Bromoethenyl)diisopropoxyborane
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The palladium catalyzed stepwise cross-coupling reaction of (E)-(2-bromoethenyl)diisopropoxyborane, readily available by bromoboration of acetylene, with α-alkoxyalkenylzinc chlorides and organic halides gives α,β-unsaturated ketones in good yields with high (E)-selectivity.
- Ogima, Masahiko,Hyuga, Satoshi,Hara, Shoji,Suzuki, Akira
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p. 1959 - 1962
(2007/10/02)
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- Synthesis of retinals labelled with 13C in the cyclohexene ring
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In this paper we report the synthesis of five retinals, specifically mono-labelled with 13C at the positions 1,2,3 and 4 and di-labelled with 13 C at the positions 16 and 17, with more than 98percent chemical purity and high 13C incorporation. (1-13C)- and (16,17-13C2) retinal were obtained in 20percent overall yield from (2-13C)- and (1,3-13C2)acetone, (2-13C)- and (3-13C)retinal were prepared in 10percent overall yield from (1-13C)- and (2-13C)acetonitrile, while (4-13C)retinal was synthesized in 17percent overall yield starting from (2-13C)acetonitrile.
- Gebhard, R.,Courtin, J. M. L.,Shadid, J. B.,Haveren, J. van,Haeringen, C. J. van,Lugtenburg, J.
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p. 207 - 214
(2007/10/02)
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- Preparation of pseudoionones
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A process is provided for the preparation of pseudoionones by the condensation reaction of citral with a ketone in the presence of lithium hydroxide catalyst.
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- SILVER MEDIATED ACETYLENIC OXY COPE REARRANGEMENT
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Electrophile initiated acetylenic oxy Cope rearrangement of diversely substituted 5-Hexen-1-yn-3-ols leads to the corresponding αδ-diethylenic aldehydes or ketones in good yields with mainly the E configuration for both double bonds.Silver nitrate and Silver trifluoromethanesulfonate appear to be most suitable electrophiles for this purpose and can be used either stoichiometrically (AgTf) or catalytically (AgNO3).
- Bluthe, Norbert,Gore, Jacques,Malacria, Max
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p. 1333 - 1344
(2007/10/02)
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- A NOVEL C10 TERPENE SYNTHON : 2-METHYL-6-METHYLENE-1,3E,7-OCTATRIENE
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The reaction of a hydroxylated base with 3-chloro-2-methyl-6-methylene-1,7-octadiene in the presence of a palladium complex and a quaternary ammonium salt gives a novel tetraene : 2-methyl-6-methylene-1,3E,7-octatriene, which is a new C10 terpene synthon.A novel access to pseudo-ionone is also described.
- Mignani, G.,Morel, D.,Colleuille, Y.,Mercier, C.
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p. 2591 - 2594
(2007/10/02)
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- Functionalization of terminal trisubstituted alkenes and derivatives thereof
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The invention relates to a process for preparing compounds having the general structure: STR1 wherein R is hydrogen or an acyclic or alicyclic fragment containing between one and about ten carbon atoms, and R1 is hydrogen or an alkyl containing between one and about four carbon atoms or an aryl group.
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- A SYNTHETIC ROUTE TO 3-METHYLTHIO-2-ALKANONES STARTING FROM 3-ALKYL-2,4-PENTANEDIONES
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An efficient preparation of a 3-methylthio-2-alkanone (1) has been realized by the reaction of a 3-alkyl-2,4-pentanedione (8) with one mol-equiv of S-methyl methanethiosulfonate (4) in the presence of excess EtONa in EtOH.Furthermore, treatment of 8 with 4 and K2CO3 in refluxing acetone, followed by addition of MeOH and heating the resulting mixture, gave 1 in a high yield.The methods were applied to synthesis of pseudoionone.
- Ogura, Katsuyuki,Sanada, Kunio,Takahashi, Kazumasa,Iida, Hirotada
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- Composition of pseudoionone and ionone based on the isomers of citral from the chlorotelomer of isoprene
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It was shown that the synthetic isomers of citral, obtained from the monoadducts of the chlorotelomer of isoprene, only form E-enones during alkaline condensation with acetone.Under the influence of mineral acids the (3E, 5Z)- and (3E, 5E)-6,10-dimethyl-3,5,9-undecatrien-2-ones formed from the Z and E isomers of citral gave a mixture of α-, β-, and γ-ionones, hydroxyionone, and 10-hydroxypseudoionones.The isomeric (3E, 5Z)-(3E, 5E)6,8,8-trimethyl-3,5,9-decatrien-2-ones and (3E, 5E)-5,10-dimethyl-3,5,9-undecatrien-2-one, obtained from the skeletal isomers of citral, do not undergo cyclization under the indicated conditions.The isolated compounds were characterized by (13)C NMR spectroscopy.
- Siirde, K. E.,Erm, A. Yu.,Vyalimyae, T. K.,Lyiveke, I. A.,Leets, K.V.
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p. 2230 - 2235
(2007/10/02)
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- TOTAL SYNTHESIS OF IONONES AND IRONES FROM 2-HYDROXYMETHYL-4-PHENYLTHIO-1-BUTENE
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A sequence of allylation, the Wacker reaction, and desulfonylation of homoallyl sulfones provided a new synthetic method for the α,β,γ,δ-unsaturated ketone system often encountered in natural products.This procedure was successfully applied to ionone and irone synthesis.
- Mandai, Tadakatsu,Nishikawa, Kengo,Yamaguchi, Hirofumi,Kawada, Mikio,Otera, Junzo
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p. 473 - 474
(2007/10/02)
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- Halogen catalyzed acetylenic oxy-cope rearrangement in N-methyl-2-pyrrolidone solvent a new industrial process for pseudoionone and its analogues
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Selective synthesis of pseudoionone was achieved by the acetylenic oxy-Cope rearrangement of 4-isopropenyl-3,7-dimethyl-6-octen-1-yn-3-ol (3) in N-methyl-2-pyrrolidone solvent containing a trace of hydrochloric acid, hydrobromic acid, iodine, ammonium bromide and ammonium chloride catalysts.
- Fujita, Yoshiji,Onishi, Takashi,Hino, Kenichi,Nishida, Takashi
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p. 1347 - 1350
(2007/10/02)
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- Isomerisation cis trans regioselective de doubles liaisons trisubstituees.
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At moderate temperatures aqueous sulphur dioxide equilibrates trisubstituted double bonds.
- Cuvigny,Herve du Penhoat,Julia
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p. 1331 - 1334
(2007/10/02)
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- Production of α,β-unsaturated ketones
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A process for the production of α,β-unsaturated ketones by reaction of an aldehyde with a ketone in the presence of a catalyst consisting essentially of zinc oxide in the liquid phase. The ketones obtained are suitable in some cases as solvents and in some cases as intermediates for the production of valuable odorants, dyes, plastics and especially natural substances.
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