- Cassis and Green Tea: Spontaneous Release of Natural Aroma Compounds from β-Alkylthioalkanones
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In depth headspace analysis of the slow degradation of β-alkylthioalkanones in ambient air led to the discovery of a novel δ-cleavage pathway, by which β-mercaptoketones are released. Since β-mercaptoketones are potent natural aroma compounds occurring in many fruits, herbs and flowers, the discovery of an enzyme-independent molecular precursor for this class of high-impact molecules is of practical importance. Moreover, the formation of β-diketones and aldehydes by concomitant oxidation at the α-sulfur-position enhances the versatility of this class of aroma precursors. A mechanistic model is proposed which suggests that the oxidative degradation occurs through a novel Pummerer-type rearrangement of initially formed persulfoxides.
- B?ttig, Sarah,Bochet, Christian G.,Egger, Timothy,Flachsmann, Felix,Gey, Olga
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- Method for continuous production of 3-methyl-3-penten-2-one in micro-channel reactor
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The invention discloses a method for continuous production of 3-methyl-3-penten-2-one in a micro-channel reactor and belongs to the technical field of organic synthesis processes. The method comprisesthe following specific steps: mixing 2-butanone with an ionic liquid [Ps-min]HSO4; simultaneously pumping a raw material acetaldehyde and a mixed solution of 2-butanone and a catalyst into a preheating module through metering pumps respectively, and introducing the components into an integral micro-channel mixer; performing uniform mixing, further introducing the components into a micro-channel reactor, and performing a reaction; and introducing the components into a cooling module, performing sample, and performing separation so as to obtain 3-methyl-3-penten-2-one. By adopting the method, aproduct can be efficiently and rapidly synthesized; the ionic liquid [Ps-min]HSO4 replaces a conventional inorganic acid to be used as a catalyst of the reaction, the reaction condition is mild, andthe product yield is high; meanwhile, the catalyst is easily separated from reaction products, the acid-base neutralization process of a conventional process is avoided, production of wastewater can be reduced, and the environment can be protected.
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Paragraph 0023-0033
(2020/03/06)
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- Facile Synthesis of Onychines
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The FeCl 3 -mediated condensation of an α-phenylenamino ester and an enone proceeds efficiently to afford a 2-phenylnicotinate. The subsequent intramolecular Friedel-Crafts reaction yielded an onychine framework. Modifications at the 2-, 3-, and 8-positions of the onychine framework were easily achieved by altering the enamino esters and enones, which facilitated the discovery of potentially bioactive compounds.
- Arita, Mao,Yokoyama, Soichi,Asahara, Haruyasu,Nishiwaki, Nagatoshi
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p. 2007 - 2013
(2019/04/26)
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- PROCESS FOR PREPARING PLATINUM ORGANOSILOXANE COMPLEXES USING AN ENONE ADDITIVE
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A platinum organosiloxane complex is prepared by a process including combining A) a platinous halide; B) a ketone; C) an enone additive distinct from any other starting materials or rearrangement products thereof; and D) a polyorganosiloxane having, per molecule, 2 to 4 silicon bonded terminally unsaturated hydrocarbon groups having from 2 to 6 carbon. The platinum organosiloxane complex prepared by the process is useful as a hydrosilylation catalyst.
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Paragraph 0023-0024
(2019/02/06)
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- Method for continuously producing 3-methyl-3-pentene-2-one by reactive distillation
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The invention discloses a method for continuously producing 3-methyl-3-pentene-2-one by reactive distillation. 2-butanone and acetaldehyde are used as raw materials, a novel microspherical polymer ionic liquid P(VB-VS)HSO4 is adopted as a catalyst, acetaldehyde and 2-butanone are subjected to an aldol condensation reaction in a reactive distillation column to generate 3-methyl-3-pentene-2-one, andthen, a reaction solution is delivered into a reduced-pressure distillation column and is subjected to reactant and product separation to obtain high-purity 3-methyl-3-pentene-2-one. According to themethod, the novel microspherical polymer ionic liquid is used as a reaction catalyst instead of traditional strong acid/alkali, so that the reaction condition is mild, the conversion rate and selectivity of acetaldehyde are high, side reactions are reduced, meanwhile, an acid-base neutralization process in a traditional process is further omitted, the energy loss and wastewater treatment are greatly reduced, and the method is capable of saving energy and environment-friendly; and the superfluous 2-butanone can be further used as a reaction raw material after being separated, so that the resource loss is reduced.
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Paragraph 0024; 0025; 0026; 0027; 0028-0035
(2019/07/10)
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- Preparation method of 3-methyl-3-penten-2-one
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The invention discloses a preparation method of 3-methyl-3-penten-2-one. The preparation method comprises the following steps: with butanone as a raw material, performing 3-position halogenation to obtain 3-halobutanone (1), then performing a ketalation reaction to obtain 3-halobutanonediol (2), then performing a Grignard reaction to obtain a Grignard reagent, performing nucleophilic addition on the Grignard reagent and acetaldehyde, and performing intramolecular dehydration under the conditions of acid catalysis and heating to obtain a target product, namely the 3-methyl-3-penten-2-one (3). The preparation method has the advantages of easy obtainment of the raw material, a wide raw material source, simpleness, low preparation cost and suitability for industrial production; by the preparation method, the problems of high preparation cost and difficult industrial production in the prior art are solved.
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Paragraph 0012-0016
(2019/01/08)
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- Method for preparing ambrotone
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The invention relates to a method for preparing ambrotone. The method includes steps of 1, synthesizing 3-methyl-3-pentene-2-ketone; 2, carrying out diene addition for preparing ambrotone intermediates; 3, carrying out cyclization reaction to prepare the ambrotone. Diene addition for preparing the ambrotone intermediates is carried out without catalysts by the aid of high-temperature gas-phase reaction. The method has the advantages that the ambrotone is prepared from raw materials beta-pinene, butanone and acetaldehyde, other organic solvents are omitted, high-pollution and high-carcinogenesis substances such as benzene and toluene are omitted, accordingly, the cost can be lowered, the quality of products can be effectively improved, the application range of the products can be effectively expanded, and Diels-Alder condensation reaction is carried out by the aid of the high-temperature gas-phase reaction; the Diels-Alder condensation reaction is carried out by the aid of the high-temperature gas-phase reaction or atomized small-molecule water drop and gas phases, catalysts such as Lewis acid or proton acid are omitted at reaction steps, accordingly, the production cost can be lowered, technological equipment can be simplified, post-reaction treatment working procedures can be shortened, and the purpose of zero sewage discharge can be truly achieved.
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Paragraph 0068; 0070-0072; 0075
(2017/09/12)
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- Preparation method of ambrotone for improving fragrance quality of ambergris
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The invention provides a preparation method of ambrotone for improving fragrance quality of ambergris. The method comprises the following steps: (1) 3-methyl-3-penten-2-ketone is synthesized; (2) an intermediate product cyclic ketone is obtained by a Diels-Alder reaction; (3) a cyclization reaction is carried out, wherein a certain amount of strong acids and lower alcohol solvents are added into a reaction vessel, the raw material intermediate product cyclic ketone is added drop by drop at a certain temperature, the reaction is carried with stirring for 5-10 hour, and the product ambrotone is obtained. Compared with the prior art, the method is advantageous in that content of an ambargris fragrance compound 1-(1,2,3,4,5,6,7,8a-octahydro-1,2,8,8-tetramethyl-2-acetonaphthone) with lower fragrance threshold value is increased from 2% to 5% or above, finally ambargris fragrance of the ambrotone product is improved; nearly no pollution generates in the production process, the yield is high, and the method is suitable for industrial production.
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Paragraph 0024
(2016/12/16)
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- A PROCESS FOR PREPARATION OF UNSATURATED KETONE
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The present invention relates to a process for preparing unsaturated ketone by using an ion exchange polymer as a catalyst. The process comprises the steps of mixing an aldehyde with a ketone and passing the mixture of aldehyde and ketone through a fixed bed catalytic reactor comprising the ion exchange polymer at a temperature of atleast 60 degree C at atmospheric pressure for a retention period of 30-50 min. The unsaturated ketone obtained from the reaction is purified by distillation and 99.5 % pure unsaturated ketone with a yield of not less than 80% is obtained.
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Page/Page column 5
(2015/03/16)
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- GREEN PROCESS FOR PRODUCING 3-METHYL-3-PENTENE-2-ONE
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The present invention relates to an improved and sustainable process for producing 3-methyl-3-pentene-2-one which is used in the synthesis of fragrance ingredients for perfumery applications.
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Paragraph 0029
(2015/05/26)
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- Stereochemistry of 2,3-Dimethyl Analogues of the Reversed Ester of Pethidine and Related Compounds: Examples of Vicinal Diaxial Methyl Groups in 2,3-Dimethylpiperidine Derivatives
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The configurations and preferred solute conformations of three diastereomeric forms of 1,2,3-trimethyl-4-phenyl-piperidin-4-ol, isolated from the product of reaction between 1,2,3-trimethyl-4-piperidone and phenyl-lithium, are established from n.m.r. and other data as α, c-2-Me, c-3-Me,r-4-OH; β, t-2-Me,c-3-Me,r-4-OH (both eq-4-Ph chairs), and γ,c-2-Me,t-3-Me,r-4-OH (boat in CDCl3).Hydrochlorides of all three isomeric forms of corresponding acetates and propionates have preferred eq-4-Ph-chair conformation in CDCl3.In case of the γ-ester and γ-piperidin-4-ol hydrochlorides and the γ-piperidin-4-ol base in (CD3)2SO, avoidance of the 2,3-dimethyl γ-gauche interaction appears to be a determinant conformational factor.Isomeric potency rankings of the propionate esters in animal antinociceptive tests are γ>α>β.
- Casy, Alan F.,Ogungbamila, Francis O.,Rostron, Christopher
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p. 749 - 754
(2007/10/02)
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- Cycloadditions of Allyl Cations, 29. Acid Catalyzed Reactions of 2,3-Dimethyl-3-penten-2-ol and Cyclopentadiene in Two Phases. Formation of Seven- and Five-membered Rings
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2,3-Dimethyl-3-penten-2-ol (3) and cyclopentadiene were stirred in dilute aqueous sulfonic acid/pentane, giving 2,3,4,4-tetramethylbicycloocta-2,6-diene (4), the epimeric 3-methylene isomers 5a, b and, for the first time, also a five-membered ring, namely 2,3,4,4-tetramethylbicycloocta-2,6-diene (6) in 69 - 73percent overall yield.The major bicyclic diene 4 was conveniently isolated as crystalline silver nitrate complex (C12H18)2*AgNO3 (41 - 44percent).In a modified approach the two phase reaction was carried out at 0 deg C, the resulting alcohols were separated by chromatography and cyclized at 50 deg C, giving an increased proportio n of the thermodynamically more stable, novel bicyclic isomer 6 (4 : 6 = 2.6 : 1).
- Hoffmann, H. M. R.,Vathke-Ernst, Heidrun
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p. 2898 - 2906
(2007/10/02)
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- Mevalonic acid analogs as inhibitors of cholesterol biosynthesis
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A series of 20 mevalonic acid analogs were synthesized and tested for their ability to inhibit cholesterol biosynthesis from [2-14C]-mevalonate in rat liver homogenates. Removal of the 5-hydroxyl group from mevalonic acid produced an active inhibitor, 3-hydroxy-3-methylpentanoic acid. Removal of the 3-hydroxyl group, addition of an aromatic group in the 3-position, or insertion of a double bond reduced inhibitory activity. Compounds with an aromatic group or halide on the 5-position were active inhibitors. The most active inhibitor was 5-phenylpentanoic acid, with 50% inhibition at 0.064 mM.
- DeBold,Elwood
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p. 1007 - 1010
(2007/10/02)
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- Stereochemistry of Addition of Allylic Grignard Reagents to 3-(Hydroxymethyl)cyclopropenes
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Allylic Grignard reagents add to the double bonds of alkyl-substituted 3-(hydroxymethyl)cyclopropenes.In the products, both the allyl group and the group (H or CO2H) replacing magnesium are cis to the hydroxymethyl group.The new carbon-carbon bond is formed preferentially at the more substituted allylic carbon of the allyl group and at the more substituted carbon of the cyclopropene double bond.
- Richey, Herman G.,Bension, Rouvain M.
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p. 5036 - 5042
(2007/10/02)
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