- Method for preparing geranic acid by oxidizing citral
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The invention provides a method for preparing geranic acid by oxidizing citral. The method comprises the following step: with a metal active component and a hydroxyl-containing azacyclo-ligand as catalysts and oxygen-containing gas as an oxidant, catalyzing citral to undergo an oxidation reaction so as to prepare the geranic acid. According to the method, the hydroxyl-containing azacyclo-ligand isadopted as a ligand, metal manganese, cobalt or copper and the like are adopted as active metals, oxidation depth is controlled, and the generation of oxidation byproducts is reduced, so the selectivity of the main product geranic acid is guaranteed, and unreacted citral is recycled. According to the method, a large amount of citral which is easy to obtain serves as a starting material, oxygen-containing gas such as air serves as a clean oxidizing agent, and the geranic acid is obtained through one-step catalytic oxidation, so a synthesis route is short, yield is high, and cost advantage is good.
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Paragraph 0035-0070
(2021/01/24)
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- Highly efficient oxidation of alcohols to carboxylic acids using a polyoxometalate-supported chromium(iii) catalyst and CO2
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Direct catalytic oxidation of alcohols to carboxylic acids is very attractive, but economical catalysis systems have not yet been well established. Here, we show that a pure inorganic ligand-supported chromium compound, (NH4)3[CrMo6O18(OH)6] (simplified as CrMo6), could be used to effectively promote this type of reaction in the presence of CO2. In almost all cases, oxidation of various alcohols (aromatic and aliphatic) could be achieved under mild conditions, and the corresponding carboxylic acids can be achieved in high yield. The chromium catalyst 1 can be reused several times with little loss of activity. Mechanism study and control reactions demonstrate that the acidification proceeds via the key oxidative immediate of aldehydes.
- Han, Sheng,Wang, Ying,Wei, Yongge,Wu, Zhikang,Yu, Han
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p. 3150 - 3154
(2020/06/19)
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- Amides as bioisosteres of triazole-based geranylgeranyl diphosphate synthase inhibitors
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Geranylgeranyl diphosphate synthase (GGDPS) inhibitors are of potential therapeutic interest as a consequence of their activity against the bone marrow cancer multiple myeloma. A series of bisphosphonates linked to an isoprenoid tail through an amide linkage has been prepared and tested for the ability to inhibit GGDPS in enzyme and cell-based assays. The amides were designed as analogues to triazole-based GGDPS inhibitors. Several of the new compounds show GGDPS inhibitory activity in both enzyme and cell assays, with potency dependent on chain length and olefin stereochemistry.
- Goetz, Daniel B.,Holstein, Sarah A.,Varney, Michelle L.,Wiemer, David F.
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- Divergent synthesis of four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid, esters and evaluation for the antifungal activity
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The four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid 2 were synthesized via the selective direct Sharpless asymmetry dihydroxylation of geraniol as the key step in 35.0%-48.0% overall yields with 91.9%-97.7% ee values for esters 4 and 31.3%-36.4% overall yields with 90.3-97.5% ee values for acids 2 using cis- and trans-geraniol as raw materials. Their structures were characterized by 1H, 13C NMR and HR-ESI-MS data. The in vivo bioassay results showed that the chiral acid (Z, S)-2 was a good lead compound with 80%-100% inhibitory rates against P. cubensis, E. graminis, P. sorghi and C. gloeosporioides at the concentration of 400μg/mL.
- Wang, Weiwei,Zhang, Xiaoteng,Zhao, Yu,Liu, Xinlei,Zhang, Zhenhua,Wang, Mingan
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- Heterologous expression of geraniol dehydrogenase for identifying the metabolic pathways involved in the biotransformation of citral by Acinetobacter sp. Tol 5
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The biotransformation of citral, an industrially important monoterpenoid, has been extensively studied using many microbial biocatalysts. However, the metabolic pathways involved in its biotransformation are still unclear, because citral is a mixture of the trans-isomer geranial and the cis-isomer neral. Here, we applied the heterologous expression of geoA, a gene encoding geraniol dehydrogenase that specifically converts geraniol to geranial and nerol to neral, to identify the metabolic pathways involved in the biotransformation of citral. Acinetobacter sp. Tol 5 was employed in order to demonstrate the utility of this methodology. Tol 5 transformed citral to (1R,3R,4R)-1-methyl-4-(1-methylethenyl)-1,3-cyclohexanediol and geranic acid. Biotransformation of citral precursors (geraniol and nerol) by Tol 5 transformant cells expressing geoA revealed that these compounds were transformed specifically from geranial. Our methodology is expected to facilitate a better understanding of the metabolic pathways involved in the biotransformation of substrates that are unstable and include geometric isomers.
- Usami, Atsushi,Ishikawa, Masahito,Hori, Katsutoshi
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p. 2012 - 2020
(2018/11/06)
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- Nitrous Oxide as a Hydrogen Acceptor for the Dehydrogenative Coupling of Alcohols
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The oxidation of alcohols with N2O as the hydrogen acceptor was achieved with low catalyst loadings of a rhodium complex that features a cooperative bis(olefin)amido ligand under mild conditions. Two different methods enable the formation of either the corresponding carboxylic acid or the ester. N2 and water are the only by-products. Mechanistic studies supported by DFT calculations suggest that the oxygen atom of N2O is transferred to the metal center by insertion into the Rh-H bond of a rhodium amino hydride species, generating a rhodium hydroxy complex as a key intermediate.
- Gianetti, Thomas L.,Annen, Samuel P.,Santiso-Quinones, Gustavo,Reiher, Markus,Driess, Matthias,Grützmacher, Hansj?rg
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supporting information
p. 1854 - 1858
(2016/02/03)
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- Synthesis and fungicidal activities of (Z/E)-3,7-dimethyl-2,6-octadienamide and its 6,7-epoxy analogues
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In order to find new lead compounds with high fungicidal activity, (Z/E)-3,7-dimethyl- 2,6-octadienoic acids were synthesized via selective two-step oxidation using the commercially available geraniol/nerol as raw materials. Twenty-eight different (Z/E)-3,7-dimethyl-2,6-octadienamide derivatives were prepared by reactions of (Z/E)-carboxylic acid with various aromatic and aliphatic amines, followed by oxidation of peroxyacetic acid to afford their 6,7-epoxy analogues. All of the compounds were characterized by HR-ESI-MS and 1H-NMR spectral data. The preliminary bioassays showed that some of these compounds exhibited good fungicidal activities against Rhizoctonia solani (R. solani) at a concentration of 50 μg/mL. For example, 5C, 5I and 6b had 94.0%, 93.4% and 91.5% inhibition rates against R. solani, respectively. Compound 5f displayed EC50 values of 4.3 and 9.7 μM against Fusahum graminearum and R. Solani, respectively.
- Yang, Mingyan,Dong, Hongbo,Jiang, Jiazhen,Wang, Mingan
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p. 21023 - 21036
(2016/01/25)
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- Selective catalytic oxidation of geraniol to citral with molecular oxygen in supercritical carbon dioxide
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Selective catalytic oxidation of geraniol to citral with molecular oxygen in supercritical carbon dioxide (scCO2) has been investigated. The catalyst used was a chromium containing mesoporous molecular sieve catalyst viz. CrMCM-41. Comparison studies were performed with CoMCM-41, PtMCM-41 and PdMCM-41 catalysts. Among the various catalysts studied, CrMCM-41 showed a high conversion of geraniol and an excellent selectivity for citral. In contrast CoMCM-41, PtMCM-41 and PdMCM-41 catalysts exhibited low conversion of geraniol. However all three catalysts compared showed similar citral selectivity to CrMCM-41. The effect of CO2 pressure and reaction temperature geraniol oxidation was studied with CrMCM-41. Supercritical CO2 medium was found to enhance the conversion of geraniol and/or yield of citral. It was noticed that the catalyst can be recycled with negligible loss of conversion.
- Dapurkar, Sudhir E.,Kawanami, Hajime,Chatterjee, Maya,Rode, Chandrasekhar V.,Yokoyama, Toshirou,Ikushima, Yutaka
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experimental part
p. 209 - 214
(2012/01/06)
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- Method for preparing an unsaturated carboxylic acid
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The invention concerns a method for preparing an unsaturated carboxylic acid from the corresponding aldehyde. More particularly, the invention aims at preparing an aliphatic carboxylic acid having at least an unsaturation conjugated with the carbonyl group. In particular, the invention concerns the preparation of geranic acid. The invention relates to a method for preparing an unsaturated carboxylic acid from the corresponding aldehyde. Said method is characterized in that it comprises a step which consists in oxidizing said aldehyde, in controlled basic medium and using molecular oxygen or a gas containing same, in the presence of a catalyst based on palladium and/or platinum and an activator based on bismuth, in conditions such that the oxidizing is carried out by diffusion process
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Page/Page column 4; 5
(2008/06/13)
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- Alcohols oxidation with hydrogen peroxide promoted by TPAP-doped ormosils
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Organically modified silica gels doped with TPAP (tetra-n-propylammonium perruthenate) are effective catalysts for the oxidation of alcohols by hydrogen peroxide at room temperature, provided that the oxidant H2O 2 solution is added slowly. The effect of the surface catalyst polarity is the opposite of that found in aerobic alcohols oxidation and is consistent with the polar nature of the primary oxidant.
- Campestrini, Sandro,Carraro, Massimo,Ciriminna, Rosaria,Pagliaro, Mario,Tonellato, Umberto
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p. 7283 - 7286
(2007/10/03)
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- Experimental and theoretical investigations for the tandem alkylation-isomerization reactions between unsaturated carboxylic acids and allyl halides
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Alkylation of dienediolates from unsaturated carboxylic acids with allylic halides when followed by solventless thermal treatment at 150 to 200°C afford rearranged products on a trend highly dependent on the α carbon substitution. Thus, 2,2-bisallylated acids with H atoms at C-2 lead to its 1,3-shift, whereas 2-methyl-2,2-bisallylated acids lead to the corresponding Cope rearrangement product. In the latter case, this tandem allylation-Cope reaction lead, in a highly regio and diastereoselective way, to products not accessible from direct alkylation. B3LYP/6-31G* energies for the compounds involved at these isomerizations are in reasonable agreement with the experiments, allowing to explain the formation of the more stable product under thermodynamic equilibrations.
- Domingo, Luis R.,Gil, Salvador,Parra, Margarita,Sáez, José A.,Torres, Mercedes
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p. 6233 - 6239
(2007/10/03)
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- Evaluation of morphogenic regulatory activity of farnesoic acid and its derivatives against Candida albicans dimorphism
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A series of farnesoic acid derivatives was prepared and their morphogenic regulatory activities were evaluated. Their inhibitory activities against yeast cell growth and yeast-to-hypha transition examined in Candida albicans cells are dependent upon the chain length as well as the substitution patterns on the isoprenoid template. The preliminary structure-activity relationship of these compounds is described to elucidate the essential structural requirements.
- Kim, Sanghee,Kim, Eunkyung,Shin, Dong-Sun,Kang, Heonjoong,Oh, Ki-Bong
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p. 895 - 898
(2007/10/03)
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- An easy and efficient method for the production of carboxylic acids and aldehydes by microbial oxidation of primary alcohols
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An easy and efficient methodology for obtaining aldehydes or carboxylic acids by oxidation of the corresponding primary alcohols with acetic acid bacteria is reported. When the biotransformation is performed in water the acids are obtained; aldehydes can be accumulated by using a water/isooctane two-liquid phase system.
- Gandolfi, Raffaella,Ferrara, Nicola,Molinari, Francesco
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p. 513 - 514
(2007/10/03)
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- Oxidation of geraniol and related volatile terpenoids with iodosylbenzene catalysed by 5,10,15,20-tetrakis(2′,6′-dichlorophenyl)porphyrinatoiron(III) chloride in dichloromethane, aqueous SDS and CTAB micelles
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Oxidation of geraniol with iodosylbenzene catalysed by 5,10,15,20-tetrakis(2′,6′-dichlorophenyl)porphyrinatoiron(III) chloride [Cl8TPPFe(III)Cl] in dichloromethane gives geranial, geranic acid and 6,7-epoxygeraniol in moderate yields. In aqueous SDS micelles, the oxidation of geraniol with iodosylbenzene in the presence of Cl8TPPFe(III)Cl gives geranial and geranic acid in high yields, whereas in CTAB micelles it gives the corresponding aldehyde and acid as well as both 6,7-epoxygeraniol and 2,3-epoxygeraniol in moderate yields. The changes in oxidation products and their yields in the presence of sodium chloride and sodium bromide have been reported in SDS micelles.
- Chauhan,Parkash, Som,Mohapatra
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p. 312 - 317
(2007/10/03)
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- Hydroxy-assisted Chemo- and Stereo-selective Epoxidation Catalysed by a Titanium Silicate Molecular Sieve (TS-1)/H2O2 System
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The TS-1/H2O2 system efficiently catalyses the hydroxy-assisted chemoselective epoxidation of α-hydroxyalkene in geraniol, and the stereoselective epoxidation of cyclopent-2-en-1-ol/cyclohex-2-en-1-ol producing the epoxide which is cis to OH with high selectivity (90:10 cis:trans).
- Kumar, Rajiv,Pais, Godwin C. G.,Pandey, Bipin,Kumar, Pradeep
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p. 1315 - 1316
(2007/10/02)
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- A Catalytic Synthesis of Nitriles from Aldehydes and Alcohols in the Presence of Aqueous Ammonia by Oxidation with N2SO4-K2S2O8
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Aromatic and conjugated aldehydes were converted to nitriles by nickel-catalyzed oxidation in the presence of aqueous ammonia with K2S2O8 under the basic aqueous conditions. this reaction could be applied to alcohols as the starting materials.
- Yamazaki, Shigakazu,Yamazaki, Yasuyuki
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p. 571 - 574
(2007/10/02)
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- ACTIVATION AND SYNTHETIC APPLICATION OF THIOSTANNANES. PROTECTION OF CARBOXYL GROUPS WITH α-METHYLCINNAMYL ALCOHOL AS A MEANS OF CHEMODIFFERENTIATION AND SELECTIVE ACTIVATION
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α-Methylcinnamyl (MEC) esters are converted into parent carboxylic acids under mild conditions, various functions being tolerated including acetoxy, siloxy, MEM, and so on.Furthermore, MEC esters are transformed into other esters through CsF-promoted alkylation of intermediary organotin carboxylates.
- Sato, Tsueno,Otera, Junzo,Nozaki, Hitoshi
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p. 2959 - 2962
(2007/10/02)
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- Electrochemical Oxidation of Primary Alcohols to Aldehydes at the Nickel Hydroxide Electrode
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Primary alcohols were oxidized to aldehydes at the nickel hydroxide electrode in an emulsion of water and a nonpolar organic solvent.Benzylic and allylic primary alcohols afforded good yields, whereas the oxidation of saturated primary alcohols was less satisfactory.
- Schneider, Roy,Schaefer, Hans-J.
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p. 742 - 743
(2007/10/02)
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- NOVEL DISTANNOXANE-CATALYZED TRANSESTERIFICATION AND A NEW ENTRY TO α,β-UNSATURATED CARBOXYLIC ACIDS
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Novel distannoxane-catalyzed transesterification reaction has been developed which affords various types of esters under very mild conditions.The reaction was applied to the stereo- and regioselective synthesis of trisubstituted α,β-unsaturated carboxylic acids.
- Otera, Junzo,Yano, Toru,Kawabata, Atsuya,Nozaki, Hitosi
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p. 2383 - 2386
(2007/10/02)
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- Reaction of Diketene with Grignard Reagents in the Presence of Cobalt Catalyst. A Convenient Method for the Synthesis of 3-Methylenealkanoic Acids Leading to Terpenoids
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Primary alkyl Grignard reagents react regioselectively with diketene in the presence of cobalt(II) iodide to afford 3-methylenealkanoic acids in good yields.The synthetic utility of this reaction is demonstrated in the syntheses of terpenoids by two methods.Utilizing the isomerization of double bond of 3-methylenealkanoic acids, geranic acid and farnesic acid were obtained in two steps.Another method, the tandem sigmatropic rearrangement of the corresponding allylic esters was used for the synthesis of C18-Cecropia juvenile hormone.
- Fujisawa, Tamotsu,Sato, Toshio,Gotoh, Yoshihiko,Kawashima, Masatoshi,Kawara, Tatsuo
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p. 3555 - 3559
(2007/10/02)
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- CITRONELLYL CITRONELLATE AND CITRONELLYL GERANATE IN THE EUROPEAN HORNET, Vespa crabro (HYMENOPTERA: VESPIDAE)
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Citronellyl citronellate and citronellyl geranate, new insect natural products, have been identified in the van der Vecht's gland of the European hornet.
- Wheeler, J. W.,Ayorinde, F. O.,Greene, A.,Duffield, R. M.
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p. 2071 - 2072
(2007/10/02)
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- Inclusion complex compound, process for its production, and method for its use
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An inclusion complex compound comprising (a) meta-cyclophane and (b) a trans-terpenoid of the formula STR1 wherein n is an integer of 1 to 9; A1 and A2 each represent (1) a hydrogen atom, (2) a halogen atom, (3) an inorganic group containing an oxygen, nitrogen or sulfur atom, (4) an organic group containing 1 to 5 carbon atoms, or (5) an organic group containing an oxygen, nitrogen or sulfur atom and 1 to 5 carbon atoms; and C* is the carbon atom of a carbonyl or methylene group, Included by the meta-cyclophane. This inclusion complex compound can be prepared by contacting the meta-cyclophane with a mixture containing the trans-terpenoid. A trans-terpenoid can be separated from a mixture containing it by utilizing an inclusion complex compound of it with meta-cyclophane.
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