- A LINEAR DITERPENE DIOL FROM LEMNA MINOR
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Four known isoprenoids were isolated from Lemna minor besides a novel diterpene which was attributed the structure (4R)-4-hydroxyisophytol by spectroscopic studies and chemical correlation.Key Word Index - Lemna minor; Lemnaceae; isoprenoids; 4-hydroxyisophytol.
- Previtera, Lucio,Monaco, Pietro
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- Method for efficiently preparing enol through selective hydrogenation of alkynol
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The invention provides a method for efficiently preparing enol through selective hydrogenation of alkynol. A conventional tank reactor and a micro-channel reactor are combined for use, and the micro-channel reactor can be used for quickly preparing an enol product after immobilizing a rare earth metal doped catalyst, so that the reaction time is shortened, and the production efficiency is improved. And a phosphine compound is added as a side reaction inhibitor to improve the selectivity.
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Paragraph 0042-0050; 0082-0097
(2021/03/24)
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- Method for preparing allyl alcohol compound by reduction of propargyl alcohol compound
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A hydrazide compound is used as a reducing agent, an organic amine is used as an auxiliary, and the propargyl alcohol compound is selectively reduced to obtain an allyl alcohol compound under the presence of a solvent and a certain temperature. The method does not need Pd catalyst which is expensive, and the reducing agent and auxiliary agent are cheap and easily available, easy to separate, free of residue in the product, simple in reaction operation process, mild in reaction condition, high in target product selectivity and the like.
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Paragraph 0063-0064
(2021/11/10)
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- An Efficient Alternative to the Total Synthesis of Isophytol
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An improved and alternative method for the total synthesis of isophytol from citral via using pseudoionone intermediate was developed and described in this manuscript. This alternative commercially viable approach involves six steps and it represents an alternative method commercially viable over existing published synthetic methods in the literature. This goal was achieved by developing and optimizing an efficient and high yield procedure for the synthesis of a key intermediate i.e. 6,10,14-trimethylpentadectrimethylpentadec-5-en-2-one, by reacting 2-methoxypro-pene with a tertiary alcohol (3,7,11-trimethyldodec-1-ene-3-ol). Isophytol was provided in 58-60% overall yield from citral with >99% purity, evaluated by TLC, GC, and NMR.
- Yerramreddy, Thirupathi R.,Yiannikouris, Alexandros
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p. 996 - 999
(2022/02/17)
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- SELECTIVE HYDROGENATION OF ALKYNOLS TO ALKENOLS IN THE PRESENCE OF A PHOSPHORUS COMPOUND
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The present invention relates to a process of hydrogenating an aIkynoI selectively to an alkenol by hydrogen using a hydrogenation catalyst which is palladium supported on a carrier in the presence of an additive which is an organic phosphorus compound bearing either a phosphine or a phosphine oxide group and with the proviso that if the additive bears a phosphino group that the additive bears two or more phosphino groups.
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Page/Page column 16-17
(2020/12/11)
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- Synthesis method and method for synthesizing plant alcohol, isoplant alcohol and geranyl geraniol by using intermediate farnesylacetone (by machine translation)
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The invention relates to a synthesis method of intermediate farnesyl acetone and a method for synthesizing vitamin E, vitamin K1, vitamin K2 side chain isovegetable alcohol, plant alcohol and geranyl geraniol by using farnesyl acetone, and concretely relates to hydrogenation of 5 - farnesyl -2 - acetone and farnesyl acetone through three Grignard reaction to obtain plant ketone. The farnesyl acetone reacts with the vinyl chloride Grignard reagent to obtain geranyl linalool, the aromatic leaf-based geraniol is rearranged under acid catalysis, or farnesyl acetone is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain geraniol. The plant alcohol is reacted with the vinyl chloride Grignard reagent to obtain the plant alcohol, and the plant alcohol is directly reacted with the hydroxyl-protected 2 - chloroethanol Grignard reagent to obtain the plant alcohol. The method has the advantages of cheap and easily available starting materials, short synthetic process steps, low product cost and the like. (by machine translation)
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Paragraph 0061; 0098-0099
(2020/07/21)
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- Preparation method for high-purity tocopherol succinate salt
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The invention relates to the field of organic synthesis, specifically to a preparation method for tocopherol succinate salt. The preparation method for the tocopherol succinate salt provided by the invention comprises the following steps: hydrogenating dl-alpha-tocopherol in the presence of a precious metal catalyst, subjecting a hydrogenated product and succinic anhydride to an esterification reaction in the presence of alkali so as to prepare a tocopherol succinate intermediate; and subjecting the tocopherol succinate intermediate to salt-forming. The preparation method for the tocopherol succinate salt provided by the invention can effectively improve the purity of a target product, can effectively reduce the content of a single impurity, and can prepare a calcium salt product with a purity capable of reaching 99.9% or above.
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Paragraph 0050; 0051; 0052; 0053
(2018/09/11)
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- HYDROGENATION PROCESS
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The present invention relates to a process of reacting specific compounds, which are defined below with hydrogen in the presence of a structured catalyst based on sintered metal fibers (SMF) coated by a ZnO layer with Pd-nanoparticles, to reactions of these specific compounds with hydrogen in the presence of said catalyst and an organic base as well as to vitamins, carotinoids, perfume ingredients, and/or food or feed ingredients prepared by using this reaction.
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Page/Page column 3
(2012/12/13)
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- NOVEL SELECTIVE HYDROGENATION CATALYST COMPRISING PALLADIUM ON POROUS SILICA GLASS AND THE USE THEREOF
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The present invention is directed to a catalyst comprising palladium on a porous Silica glass as carrier, as well as to the use of such catalyst for the selective hydrogenation of alkines to alkenes.
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Page/Page column 2
(2011/10/12)
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- HYDROGENATION PROCESS
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The present invention relates to a process of reacting specific compounds, which are defined below with hydrogen in the presence of a structured catalyst based on sintered metal fibers (SMF) coated by a ZnO layer with Pd-nanoparticles, to reactions of these specific compounds with hydrogen in the presence of said catalyst and an organic base as well as to vitamins, carotinoids, perfume ingredients, and/or food or feed ingredients prepared by using this reaction.
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Page/Page column 8-9
(2011/08/21)
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- An efficient procedure for the 1,3-transposition of allylic alcohols based on lithium naphthalenide induced reductive elimination of epoxy mesylates
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An efficient protocol for the 1,3-transposition of allylic alcohols has been developed. The method is based on the pretransformation of allylic alcohols into the corresponding epoxy mesylates, followed by the reductive elimination of the resulting epoxy mesylates by using lithium naphthalenide (LN) as a reducing agent. Georg Thieme Verlag Stuttgart.
- Wu, Yen-Ku,Liu, Hsing-Jang,Zhu, Jia-Liang
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p. 621 - 623
(2008/12/22)
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- Method for preparing vitamin e
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The invention concerns a novel method for preparing vitamin E. More particularly, it concerns a novel method for the condensation of Arimethylhydroquinone and isophytol.
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- Preparation of higher alpha, beta-unsaturated alcohols
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Higher α,β-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetatesor diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.
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- Hydrogenation on granular palladium-containing catalysts: I. Hydrogenation of tertiary acetylene alcohols
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Commercial granular palladium catalyst (0.5% of Pd on γ-Al 2O3) was modified by treating with zinc acetate (type 1) or successively with zinc acetate and ammonia (type 2). The treatment significantly increased the hydrogenation selectivity for a triple bond into a double bond: to 85.3-93.1% with the type 1 catalyst and to 96.3-97.8% with the type 2 catalyst. A construction of an autoclave with a fixed bed of the granular catalyst is described.
- Tolkacheva,Kislyi,Taits,Semenov
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p. 150 - 152
(2007/10/03)
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- Preparation of C10-C30-alkenes by partial hydrogenation of alkynes over fixed-bed supported palladium catalysts
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Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.3 to 200 bar over fixed-bed supported palladium catalysts which are obtainable by heating the support material in the air, cooling, applying a palladium compound and, if required, additionally other metal ions for doping purposes, molding and processing to give monolithic catalyst elements, by a process in whichA) alkynes of 10 to 30 carbon atoms are used as starting compounds,B) the palladium compound and, if required, the other metal ions are applied to the support material by impregnation of the heated and cooled support material with a solution containing palladium salts and, if required, other metal ions and subsequent drying, andC) from 10 to 2000 ppm of carbon monoxide (CO) are added to the hydrogenation gas or a corresponding amount of CO is allowed to form in the liquid phase by slight decomposition of a compound which is added to the reaction mixture and eliminates CO under the reaction conditions.The process is particularly advantageous if the partial hydrogenation is carried out in a tube reactor by the trickle-bed or liquid phase procedure with product recycling at cross-sectional loadings of from 20 to 500 m3/m2*h. The process is particularly suitable for the preparation of 3,7,11,15-tetramethyl-1-hexadecen-3-ol (isophytol), 3,7,11-trimethyl-l-dodecen-3-ol (tetrahydronerolidol), 3,7,11-trimethyl-1,4-dodecadien-3-ol, 3,7,11-trimethyl-1,6-dodecadien-3-ol (dihydronerolidol), 3,7-dimethyloct-1,6-dien-3-ol or 3,7-dimethyloct-1-en-3-ol from the corresponding alkynes.
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- Development of synthetic routes to D,L-α-tocopherol (vitamin E) from biologically produced geranylgeraniol
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The use of the biologically derived diterpene alcohol geranylgeraniol was explored as an alternative to petrochemical-based isophytol as a side-chain synthon for producing D,L-α-tocopherol. Two routes were studied, both of which begin with allylic epoxidation followed by olefin hydrogenation to give epoxyphytol. Epoxyphytol can be reduced with Red-Al to provide phytan-1,3-diol which upon acid-catalyzed condensation with trimethylhydroquinone gives vitamin E in fair yield. In a higher-yielding process, epoxyphytol was deoxygenated with methylrhenium trioxide/triphenylphosphine to generate a mixture of phytol and isophytol (> 90% yield from geranylgeraniol). This mixture can serve as a "plug-in" replacement for isophytol in the final step of the currently practiced vitamin E chemistry. The use of methylrhenium trioxide to catalyse dehydration of vinyl dialkyl carbinols to 1,3-dienes was also demonstrated.
- Hyatt, John A.,Kottas, Gregg S.,Effler, Janet
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p. 782 - 787
(2013/09/06)
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- Ozonolysis of alkenes and study of reactions of polyfunctional compounds. LIX. New approach to synthesis of isophytol and (E,E)-geranyllinalool, isoprenoid synthons for the α-tocopherol and (E,E)-α-tocotrienol
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A new approach was developed to the synthesis of racemic isophytol and (E,E)-geranyllinalool starting from a product of partial ozonolysis of (E,E,E)-l,5,9-cyclododecatriene.
- Odinokov,Akhmetova,Savchenko,Mallyabaeva,Lobanova
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p. 1099 - 1101
(2007/10/03)
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- Selective Hydrogenation of Dehydrolinalool and Dehydroisophytol in a Liquid Film Moving over Pd-Ru Foil
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Selective hydrogenation of dehydrolinalool (DHL) and dehydroisophytol (DHI) on a catalyst made of a palladium-ruthenium (6 wt percent) alloy rolled into a foil 0.05 mm thick was studied.Hydrogenation of the acetylene alcohols was conducted without a solvent in a flow reactor, while a film of the liquid moved over the surface of the catalyst rolled up into a frustum of a cone rotating about its axis.The compounds were hydrogenated at several temperatures by hydrogen, which reached the surface of the catalyst by diffusion through the liquid.Hydrogenation selectivity was improved by adding CO to hydrogen.In the presence of CO, the reaction in the kinetic region was first-order with respect to hydrogen and zeroth-order with respect to the alcohols undergoing hydrogenation.Under identical conditions, DHL was hydrogenated more selectively and at a rate two times higher than DHI.Maximum selectivity (0.995) was attained at 383 K; hydrogen and CO pressures were 0.15 and 0.05 MPa, respectively, for DHL and 0.05 and 0.25 MPa for DHI.In the presence of CO, hydrogenation of DHL and DHI followed qualitatively similar patterns.
- Maganyuk, A. P.,Gizhevskii, S. F.,Gryaznov, V. M.
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p. 1244 - 1247
(2007/10/03)
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- Cleavage of 2,3-Epoxyalkylhalides by the Sonochemical Zinc-Copper Couple
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2,3-Epoxyalkylhalides are readily transformed into allylic alcohols when sonicated in the presence of a zinc-copper couple in aqueous ethanol.
- Sarandeses, Luis A.,Mourino, Antonio,Luche, Jean-Louis
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p. 818 - 820
(2007/10/02)
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- KINETICS AND SELECTIVITY OF THE HYDROGENATION OF A C20 ACETYLENIC ALCOHOL (DEHYDROISOPHYTOL) ON SUPPORTED PALLADIUM CATALYSTS UNDER HYDROGEN PRESSURE IN A FLOW SYSTEM.
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The lack of a general mechanistic and kinetic analysis of the multistep reaction of dehydroisophytol in a tube reactor makes it difficult to choose a selective catalyst system or to determine the optimum conditions for the preparation of the desired products. For this reason the authors have carried out an investigation of the effect of various process parameters (PH//2, T, reactant feed rates, etc. ) on the kinetics and selectivity of the hydrogenation of dehydroisophytol in the presence of industrial supported palladium catalysts (0. 75% Pd on ShAS silica gel; 0. 5% Pd on ShN-2, P-5 silica gel) in a flow system by the 'streaming' method. The data reveal that the composition of the catalysate mixture for the hydrogenation of compound in 0. 5% Pd/ShN-2 changes appreciably in proportion to the rate of addition of excess hydrogen. For instance, as the rate of bubbling of hydrogen is increased from 60 to 100 cm**3/min, the concentration of the C//2//0 saturated alcohol increases from 20. 0-21. 0 to 39. 0-40. 0%, and the concentration of compound decreases from 49. 0-50. 0 to 42. 0-43. 0%. The amount of unreacted starting material is also reduced, from 30. 0-31. 0 to 18. 0-17. 0%. Based on experimental evidence it is concluded that the use of these catalysts under stationary (fixed-bed) conditions significantly increases the productivity of the process (20-30 times), although they are noticeably inferior to the industrially used catalysts with respect to selectivity. This work is pertinent to synthesis of vitamins.
- Omarkulov,Mukataev,Goncharova,L'dokova,Sokol'skii
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p. 1409 - 1412
(2007/10/02)
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- SEMIHYDROGENATION OF ACETYLENES; MODIFIED LINDLAR CATALYST
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The effect of doping Lindlar catalyst with different metal salts (shown in Table 1) on selectivity, during semihydrogenation of some acetylenes to the corresponding olefins, has been studied.Lindlar catalyst modified with MnCl2 has been found to be more selective and reproducible.
- Rajaram, J.,Narula, A. P. S.,Chawla, H. P. S.,Dev, Sukh
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p. 2315 - 2322
(2007/10/02)
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- 2-HYDROXYMETHYL-4-PHENYLTHIO-1-BUTENE AS A KEY COMPOUND FOR TOTAL SYNTHESIS OF ACYCLIC TERPENOIDS
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A new total synthesis of myrcene, citral, squalane, and isophytol employing 2-hydroxymethyl-4-phenylthio-1-butene as a starting material is described.
- Mandai, Tadakatsu,Yamaguchi, Hirofumi,Nishikawa, Kengo,Kawada, Mikio,Otera, Junzo
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p. 763 - 764
(2007/10/02)
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- HYDROGENATION OF ACETYLENIC COMPOUNDS IN THE PRESENCE OF A COMPLEX CATALYST BASED ON NICKEL STEARATE AND TRIETHYLALUMINUM
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Hydrogenation in the presence of a catalytic system based on nickel stearate and triethylaluminum was investigated for the following acetylenic compounds: Phenylacetylene; 1-hexyne; dimethylethynylcarbinol; dimethylvinylethynylcarbinol; 3,7,11,15-tetramethyl-1-hexadecyn-3-ol.The hydrogenation rate of the triple bond decreases in the order 1-hexyne > phenylacetylene > dimethylethynylcarbinol.The selectivity of the hydrogenation of the alcohols increases with increase in the molar ratio of the components of the Al(C2H5)3/Ni(C17H35COO)2.
- Izteleuova, M. B.,Noskova, N. F.,Sokol'skii, D. V.,Gafarova, N. A.,Nadirov, N. K.
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p. 975 - 978
(2007/10/02)
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- Synthesis of Phytol
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Ethyl 3,7,11-trimethyldodecanoate (IV), obtained from geranylacetone (II) by modified Wittig condensation with ethyl diethylphosphonoacetate followed by catalytic hydrogenation, on LAH reduction yields the carbinol (V).V on alkylation through its mesylate with ethyl monosodioacetoacetate and subsequent decarbethoxylation with alkoholic KOH affords 6,10,14-trimethylpentadecan-2-one (VIII).VIII on treatment with vinylmagnesium bromide followed by treatment with PTS in acetic anhydride and glacical acetic acid yields 3,7,11,15-tetramethyl-2(E)-hexadecen-1-ol acetate (X) which on saponification furnishes phytol (I).
- Vig, O. P.,Bari, S. S.,Vig, Rashmi,Dua, D. M.
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p. 453 - 455
(2007/10/02)
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