5704-20-1Relevant academic research and scientific papers
Selective Hydrogenation of Diketones on Supported Transition Metal Catalysts
Carrara,Badano,Vailard,Vera,Quiroga
, p. 461 - 470 (2019/11/13)
Abstract: The hydrogenation of α-diketones yields α-hydroxyketones or vic-diols, both compounds of great interest in fine chemistry. The reaction tests were the liquid phase hydrogenation of 2,3-butanedione and 2,3-pentanedione at mild conditions. The objectives of this work were evaluating the effect over the activity and selectivity of: (a) different transition metallic phase based catalysts supported on activated carbon, (b) the symmetry of the reactants and (c) solvents. The physicochemical characterization of the catalysts was carried out by ICP, XRD, TEM, N2 adsorption and XPS. The keto-enol equilibrium of diketones was studied by 1H-NMR. All the catalysts were active in both reactions. In terms of activity, Pt and Rh were the best active phases. For both reactants the highest selectivity towards hydroxyketones were achieved with Pd, while Ru was the most selective towards the diol. Both the activity and selectivity followed similar patterns in the hydrogenation of both diketones. The greater activity of Pt was attributed to the high dispersion of the active metal phase in this catalyst and the high efficiency of Pt for C = O bond reduction. The high selectivity of the Pd catalysts towards the intermediate product was attributed to many effects: (i) a lower interaction of the hydroxyketone with the active site as compared to the diketone, (ii) the easy reducibility of the C = C double bond on Pd, provided by the keto-enol tautomerism of diketones.
Preparation Method for 2,3-pentanedione
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Paragraph 0018; 0019; 0024; 0025; 0029, (2019/04/25)
A preparation method for 2,3-pentanedione, including the steps of adding one or both of 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone into water and conducting mixing, and introducing ozone at the temperature of 3-20° C. for a reaction to obtain 2,3-pentanedione. The synthesis process of the present invention uses ozone for oxidizing a mixture containing 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone, acetic acid is used as a cocatalyst, reaction conditions are mild, the operation process is simple, the product yield is high, and the cost is low.
Preparation method of 2,3-pentanedione
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Paragraph 0004; 0017-0019; 0024-0026; 0031-0033, (2018/09/08)
The invention discloses a preparation method of 2,3-pentanedione. The preparation method comprises the following steps: one or two of 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone is/are added to water and uniformly mixed with water, ozone is introduced at the temperature of 3-20 DEG C for a reaction, and 2,3-pentanedione is obtained. According to the synthesis process, ozone is adopted to oxidize the mixture containing 3-hydroxy-2-pentanone and 2-hydroxy-3-pentanone, acetic acid is adopted as a cocatalyst, reaction conditions are mild, and operation process is simple; product yield is high;cost is low; the method has the advantages of being safe and environmentally friendly, and no wastewater is produced.
Synthesis of aggregation pheromone components of cerambycid species through α-hydroxylation of alkylketones
Heguaburu, Viviana,do Carmo, Hugo,Parpal, Florencia,Amorós, María Eugenia,González, Andrés
supporting information, p. 1738 - 1741 (2017/04/13)
The synthesis of 3-hydroxy-2-hexanone and 2,3-hexanediol, two components of the aggregation pheromone of several cerambycid species, is disclosed in here. Starting from 2-hexanone, through an α-hydroxylation using (diacetoxyiodo)benzene, 3-hydroxy-2-hexanone is obtained in good yield. Further reduction of this compound, gives 2,3-hexanediol in excellent yield. A study of the α-hydroxylation reaction of several alkylketones using an hypervalent iodine reagent is also disclosed in here. The synthesis of optically active compounds (R)- and (S)-3-hydroxy-2-hexanone was achieved starting from 2-hexanone with nitrosobenzene and L- and D-proline respectively, in several reaction media.
Chemoenzymatic synthesis of aroma active 5,6-dihydro- and tetrahydropyrazines from aliphatic acyloins produced by baker's yeast
Kurniadi, Toshinari,Bel Rhlid, Rachid,Fay, Laurent-Bernard,Juillerat, Marcel-Alexandre,Berger, Ralf Guenter
, p. 3103 - 3107 (2007/10/03)
Twenty-five acyloins were generated by biotransformation of aliphatic aldehydes and 2-ketocarboxylic acids using whole cells of baker's yeast as catalyst. Six of these acyloins were synthesized and tentatively characterized for the first time. Subsequent chemical reaction with 1,2-propanediamine under mild conditions resulted in the formation of thirteen 5,6-dihydropyrazines and six tetrahydropyrazines. Their odor qualities were evaluated, and their odor thresholds were estimated. Among these pyrazine derivatives, 2-ethyl-3,5-dimethyl-5,6-dihydropyrazine (roasted, nutty, 0.002 ng/L air), 2,3-diethyl-5-methyl-5,6-dihydropyrazine (roasted, 0.004 ng/L air), and 2-ethyl-3,5-dimethyltetrahy-dropyrazine (bread crustlike, 1.9 ng/L air) were the most intensive-smelling aroma active compounds.
Bacterial biotransformation of isoprene and related dienes
Boyd, Derek R.,Clarke, David,Cleij, Marcel C.,Hamilton, John T.G.,Sheldrake, Gary N.
, p. 673 - 685 (2007/10/03)
The bacterium Pseudomonas putida ML 2 was used in the oxidative biodegradation of the acyclic dienes isoprene, trans-piperylene, cis-piperylene, and 1,3-butadiene. Regioselective dioxygenase-catalyzed dihydroxylation of alkenes yielded vicinal diols in the preferred sequence monosubstituted 〉 cis-disubstituted 〉 gem-disubstituted 〉 trans-disubstituted. The isolated diol metabolites had an excess of the R configuration (9-97% ee), and further diol oxidation was controlled by addition of propylene glycol as an inhibitor. Stereoselectivity using the ML2 strain resulted from both enzymatic asymmetric alkene dihydroxylation and kinetic resolution of diols. Enantioselective oxidation of the allylic secondary alcohol group of R configuration yielded the corresponding unsaturated ketoalcohol; the residual diol was recovered with a large excess (≥ 93% ee) of the S configuration. In addition to the enzymatic diene oxidation steps yielding unsaturated diols and ketoalcohols, evidence was also found of enzymatic alkene hydrogenation to yield saturated ketoalcohols and diols.
Studies on Pyruvate Decarboxylase: Acyloin Formation from Aliphatic, Aromatic and Heterocyclic Aldehydes
Crout, David H. G.,Dalton, Howard,Hutchinson, David W.,Miyagoshi, Masanori
, p. 1329 - 1334 (2007/10/02)
Evidence is described that supports the view that the enzyme responsible for acyloin formation from aldehydes in the yeast Saccharomyces cerevisiae is pyruvate decarboxylase.
Stereoelectronic Control of the Base-catalysed Rearrangement of 2-Hydroxy-3-oxocarboxylates
Crout, David H. G.,Lee, Edward R.,Pearson, David P. J.
, p. 381 - 385 (2007/10/02)
The stereochemistry of the alkyl-catalysed rearrangement of α-acetohydroxybutyrate (2-ethyl-2-hydroxy-3-oxobutanoate) was studied.The rearrangement was found to proceed via a transition state in which a syn arrangement of the C-O bonds is preferred over the anti arrangement by a factor of >/= 2:1.
Absolute Configuration of the Product of the Acetolactate Synthase Reaction by a Novel Method of Analysis using Acetolactate Decarboxylase
Crout, David H. G.,Lee, Edward R.,Rathbone, Daniel L.
, p. 1367 - 1369 (2007/10/02)
Pyruvate and 2-oxobutanoate were incubated with acetolactate synthase in the presence of acetolactate decarboxylase .The exclusive production of 3-hydroxypentan-2-one showed that the α-acetohydroxybutyrate (2-ethyl-2-hydroxy-3-oxobutanoate) produced by acetolactate synthase had the (S)-configuration.The ability of acetolactate decarboxylase to catalyse rearrangement of the (R)-enantiomer of substrates via carboxylate migration was investigated using -α-acetolactate, in which the degeneracy of the rearrangement of the normal substrate was broken by isotopic labelling.The predicted sequential formation of - and -acetoin was observed.
Baker's Yeast Reduction of 1,2-Diketones. Preparation of Pure (S)-(-)-2-Hydroxy-1-phenyl-1-propanone
Chenevert, Robert,Thiboutot, Sonia
, p. 1191 - 1192 (2007/10/02)
1,2-Diketones are readily reduced by fermenting baker's yeast but the reactions proceed with little selectivity.One notable exception is the reduction of 1-phenyl-1,2-propanedione which affords pure (S)-(-)-2-hydroxy-1-phenyl-1-propanone in good yield.
