- Preparation method of 2-methyl-4-acetoxy-2-butenal with thermal stability
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The invention discloses a preparation method of 2-methyl-4-acetoxy-2-butenal with thermal stability, which comprises the following steps: (1) carrying out gas-solid-liquid three-phase hydroisomerization reaction on 2-methylene-4-acetoxybutyraldehyde and a solvent under the action of a catalyst to generate 2-methyl-4-acetoxy-2-butenal; (2) after the reaction reaches a specified conversion rate, terminating the reaction, conducting cooling and filtering out the catalyst; and (3) rectifying and separating the solvent, hydrogenation by-products and unreacted raw materials in the system to obtain the product 2-methyl-4-acetoxy-2-butenal. In the step (1), active hydrogen in the used solvent is controlled to be less than or equal to 100mgKOH/kg in terms of hydroxyl value content. The 2-methyl-4-acetoxy-2-butenal provided by the invention is good in thermal stability, low in loss rate in a rectification separation process and low in cis-isomer content, and can better meet downstream requirements.
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Paragraph 0058-0077
(2021/11/06)
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- Synthetic method of trans-4-acetoxyl-2-methyl-2-butene-1-aldehyde
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The invention discloses a synthetic method of trans-4-acetoxyl-2-methyl-2-butene-1-aldehyde. The method comprises the steps that 3,4-diacetoxy-1-butene and synthetic gas are used as raw materials, a formylation reaction is carried out at the temperature o
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Paragraph 0026; 0039; 0040
(2016/12/22)
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- Synthesis of fluorescently tagged isoprenoid bisphosphonates that inhibit protein geranylgeranylation
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Geminal bisphosphonates can be used for a variety of purposes in human disease including reduction of bone resorption in osteoporosis, treatment of fractures associated with malignancies of the prostate, breast, and lung, and direct anticancer activity ag
- Maalouf, Mona A.,Wiemer, Andrew J.,Kuder, Craig H.,Hohl, Raymond J.,Wiemer, David F.
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p. 1959 - 1966
(2007/10/03)
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- Structure assignment of lagunapyrone B by fluorous mixture synthesis of four candidate stereoisomers
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Techniques of fluorous mixture synthesis have been used to make four candidate stereoisomers for the natural product lagunapyrone B. A quasiracemic mixture of vinyl iodides whose component configurations at C19-21 were encoded by fluorous silyl groups was
- Yang, Fanglong,Newsome, Jeffery J.,Curran, Dennis P.
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p. 14200 - 14205
(2008/02/10)
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- Synthesis of (2E)-4-hydroxy-3-methylbut-2-enyl diphosphate, a key intermediate in the biosynthesis of isoprenoids
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The synthesis of (2E)-4-hydroxy-3-methylbut-2-enyl diphosphate (HMBPP) was described by regioselective hydroxylation and diphosphorylation of dimethylallyl alcohol. The synthesis started from commercially available 3-methylbut-2-en-1-ol. The 1-alcohol function of starting material was converted to the acetate by treatment with pyridine acetic anhydride. Selective allylic hydroxylation was achieved using selenium dioxide and tert-butyl hydro-peroxide.
- Ward, Jane L.,Beale, Michael H.
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p. 710 - 712
(2007/10/03)
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- New retinoid analogs from δ-pyronene, a natural synthon
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δ-Pyronene (1), a readily available terpenic synthon, is an excellent raw material for the preparation of numerous terpenic intermediates. Original retinoid analogs such as 'iso'-retinyl acetate (5), 'iso'-retinal (6) and ethyl 'iso' retinoate (7), in which the cyclogeranyl moiety is functionalized in an unusual position, were prepared from δ-pyronene.
- Lambertin, Frederic,Wende, Martin,Quirin, Marie Jeanne,Taran, Martine,Delmond, Bernard
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p. 1489 - 1494
(2007/10/03)
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- Process for producing branched aldehydes
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It is provided a process for industrially advantageously producing a branched aldehyde represented by the formula; STR1 ?wherein Y represents an acyl group of two or more carbon atoms; and X represents an acyloxymethyl group represented by --CH2/sub
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- Process for producing 4-substituted-2-butenals
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Described is a process for producing a 4-substituted-2-butenal represented by the following formula (1); STR1 (wherein X represents an acyloxy group or halogen atom; R represents hydrogen atom, an aliphatic hydrocarbon group or an aromatic hydrocarbon gro
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- Process for the manufacture of a gamma-halotiglic aldehyde
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A novel process for the manufacture of a γ-halotiglic aldehyde HalH2 C--CH=C(CH3)--CHO ?I!, wherein Hal signifies chlorine or bromine, comprises haloalkoxylating a 1-alkoxy-2-methyl-1,3-butadiene H2 C=CH--C(CH3)
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- Process for producing aldehyde derivatives
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The present invention provides a novel process for producing 4-acyloxy-2-methyl-2-buten-1-al readily in high yield from a readily available inexpensive industrial starting compound without using special reaction apparatuses and conditions.
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- Process for producing vitamin A derivatives
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The present specification relates to an industrially advantageous process for producing vitamin A derivatives which are useful as medicaments, feed additives, food additives and the like. The process provides vitamin A derivatives, particularly all-trans vitamin A derivatives in high yield and purity.
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- Process for the manufacture of gamma-acetoxytiglic aldehyde
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A novel process for the manufacture of γ-acetoxytiglic aldehyde ("C5 -aldehyde"), which is known as an important starting material for the production of vitamin A acetate from a (β-ionylidenethyl)triphenylphosphonium halide and C5 -a
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- Process for producing α,β-unsaturated aldehydes
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The present invention relates to a process for producing an α,β-unsaturated aldehyde which comprises subjecting an allyl-hexamethylenetetraammonium derivative to hydrolysis in water and an organic solvent homogeneously immiscible with water. The resulting α,β-unsaturated aldehyde is useful as medicaments, flavorings, etc., or as raw materials for their production.
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- Process for preparing α, β-unsaturated aldehydes
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A process for preparing α,β-unsaturated aldehydes of the general formula (I) STR1 in which R1, R2 and R3 are independently a hydrogen atom, or an alkyl or alkenyl group with or without being substituted with a lower acyloxy group. The aldehyde of the general formula (I) is prepared by reaction between an allylic chloride of the following general formula (IIa) STR2 in which R1, R2 and R3 have, respectively, the same meanings as defined above, and an amine oxide selected from the group consisting of tri(lower alkyl)amine N-oxides of the formula, in which R4 represents a lower alkyl group having from 2 to 4 carbon atoms, and N-lower alkylmorpholine N-oxides of the following formula STR3 in which R5 represents a lower alkyl group having from 1 to 4 carbon atoms. Alternatively, the aldehyde of the formula (I) is obtained by reaction between an allylic chloride of the following general formula (IIb) STR4 in which R1, R2 and R3 have, respectively, the same meanings as defined above, and an amine oxide selected from the group consisting of tri(lower alkyl)amine N-oxides of the formula, in which R4 has the same meaning as defined above, and N-lower alkylmorpholine N-oxides of the following formula STR5 in which R5 has the same meaning as defined above, in the presence of an alkali metal iodide or a copper halide.
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- Acyloxy-2-butenes and their preparation
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Acyloxy-2-butenes of the formula STR1 where R1, R3 and R4 are each hydrogen or alkyl of 1 to 5 carbon atoms, R2 is alkyl of 1 to 5 carbon atoms, R5 is hydrogen, alkyl of 1 to 5 carbon atoms or R6 --CO--O, and R6 and R7 are each hydrogen, alkyl of 1 to 5 carbon atoms, phenyl or cyclohexyl, the preparation of these acyloxy-2-butenes by reaction of 1-acyloxy-1,3-butadienes of the formula STR2 with carboxylic acids of the formula R7 --COOH and oxygen at 50°-180° C. in the presence of catalysts containing palladium or platinum, and the use of the compounds of the formula I, where R1, R3, R4 and R5 are hydrogen, R2 and R6 are methyl and R7 is methyl or ethyl, for the preparation of 4-acyloxytiglic aldehydes.
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- Regio- and Stereo-selective Oxidation of gem-Dimethyl Olefins via -Sigmatropic Rearrangement of Allyl Amine Oxides
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Highly regio- and stereo-selective oxidation sequences are described for the efficient conversion of the gem-dimethyl olefin terminus of acyclic terpenes to terminal trans-allylic alcohols and trans α,β-unsaturated aldehydes.
- Inoue, Seiichi,Iwase, Norimichi,Miyamoto, Osamu,Sato, Kikumasa
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p. 2035 - 2038
(2007/10/02)
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- A Convenient Method for Conversion of Allylic Chlorides to α,β-Unsaturated Aldehydes
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Tertiary amine N-oxides were found to be effective for converting chlorides to aα,β-unsaturated aldehydes.
- Suzuki, Shigeaki,Onishi, Takashi,Fujita, Yoshiji,Misawa, Hiromitsu,Otera, Junzo
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p. 3287 - 3288
(2007/10/02)
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- Retinoids and Carotenoids, V.- Synthesis of Modified Retinals
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The syntheses of 13-demethyl-13-ethyl-, 13-demethyl-13-propyl-, 13-demethyl-, 13-demethyl-14-methyl-, and 14-methylretinal are described.The UV spectra of some geometric isomers of these compounds are discussed.
- Bestmann, Hans Juergen,Ermann, Peter,Rueppel, Hartmann,Sperling, Walter
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p. 479 - 498
(2007/10/02)
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- REGIO- AND STEREOSELECTIVE OXIDATION OF ENE-TYPE CHLORINATED OLEFINS.
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Regio- and stereoselective oxidation of ene-type chlorinated olefins has been achieved by using potassium 2-propanenitronate as an oxidant and tetrakis(triphenylphosphine)palladium as a catalyst.
- Suzuki, Shigeaki,Onishi, Takashi,Fujita, Yoshiji,Otera, Junzo
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p. 1123 - 1130
(2007/10/02)
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- Ruthenium-catalysed Oxidation of Allyl Alcohols by Molecular Oxygen
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Ruthenium(II) catalyses the homogeneous oxidation of allyl alcohols to carbonyl compounds by molecular oxygen under mild conditions.
- Matsumoto, Masakatsu,Ito, Satoru
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p. 907 - 908
(2007/10/02)
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- Preparation of 4-acyloxy-2-methyl-crotonaldehydes
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A process for the preparation of a 4-acyloxy-2-methyl-crotonaldehyde of the formula STR1 where R is hydrogen or an aliphatic radical of 1 to 5 carbon atoms, by reacting a 1,1,4-triacyloxy-2-methyl-but-2-ene of the formula STR2 where R1 and Rsu
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- Preparation and photolysis of deuterium-labelled rhodopsin analogues
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The compounds 18- and 19-trideutero-11-cis-retinal, > 99percent pure, with over 98percent and 99percent trideuterium incorporation were synthesized together with the corresponding all-trans derivatives.Rhodopsins were prepared from bovine opsin and 18- and 19-trideutero-11-cis-retinal, 18- and 19-trideutero-all-trans-retinal were isolated as oximes after photolysis of the corresponding rhodopsins.The oximes showed the same deuterium incorporation as the starting 18- and 19-trideutero-11-cis-retinals and as those oximes obtained by denaturation of 18- and 19-trideuterorhodopsin in the dark.These results demonstrate that during rhodopsin photolysis no detectable exchange of D or H occurs at carbon atoms 18 and 19.These facts, together with Resonance Raman data of 18-trideutero-bathorhodopsin and 5-demethylbathorhodopsin, establish that the primary step in rhodopsin photochemistry is not a phototautomerization involving the 5-CH3 group.With respect to the possibility that the primary step is a phototautomerization involving the 9-CH3 group, the situation is less clear.At this time experimental evidence of the various research disciplines is insufficiently conclusive to establish unambiguously which of the two possibilities, cis-trans photoisomerization or phototautomerization involving the 9-CH3 group, is the primary event in visual photochemistry.
- Fransen, M. R.,Palings, I.,Lugtenburg, J.,Jansen, P. A. A.,Groenendijk, G. W. T.
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p. 384 - 391
(2007/10/02)
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- Method of preparing E-4-acetoxy-2-methyl-2-butenal
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E-4-acetoxy-2-methyl-2-butenal is prepared by: (1) preparation of an intermediate allylic halide from isoprene; and (2) reaction of the allylic halide with dimethyl sulfoxide in the presence of a non-nucleophilic base to form the desired product.
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- Novel cyano compounds
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A novel conjugated diene bisfunctionalization process wherein a nitro group and a hydroxyl group in the form of an ester are introduced into the conjugated diene molecule by treatment of conjugated dienes with nitric acid in the presence of an acid anhydride. The novel compounds produced by this process and transformation products thereof, are useful as bactericides and fungicides and valuable organic synthesis intermediates, A novel procedure for the production of nitriles and γ-acetoxytiglic aldehyde is disclosed.
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