- A two-step chemoenzymatic synthesis of the natural pheromone (+)-sitophilure utilizing isolated, NADPH-dependent ketoreductases
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Isolated, NADPH-dependent ketoreductases were used for the synthesis of the aggregation pheromone of the pests rice weevil (Sitophilus oryzae L.) and maize weevil (Sitophilus zeamais M.). This is the easiest and most straight forward synthesis of pheromon
- Kalaitzakis, Dimitris,Rozzell, J. David,Kambourakis, Spiros,Smonou, Ioulia
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- USE OF BIOLOGICAL SYSTEMS FOR THE PREPARATION OF CHIRAL MOLECULES IV : A TWO-STEP CHEMOENZYMATIC SYNTHESIS OF A NATURAL PHEROMONE (4R,5S)-(-)-4-METHYL 5-HYDROXY HEPTAN 3-ONE, SITOPHILURE.
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Reduction of 4-methyl heptan 3,5-dione 2 by resting cells of Geotrichum candidum provides natural sitophilure (4R,5S)-(-)-4-methyl 5-hydroxy heptan 3-one 1 under anaerobic conditions.Diastereoisomer (4S,5S)-(+)-4-methyl 5-hydroxy heptan 3-one 1a is obtained under aerobic conditions.Starting β-diketone is easily obtained by a one-pot synthesis.Good yield and high enantiomeric excess are obtained for the natural pheromone.
- Fauve, Annie,Veschambre, Henri
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- Total synthesis of cyercene A and the biomimetic synthesis of (±)-9,10-deoxytridachione and (±)-ocellapyrone A
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This paper summarises our detailed study towards the biomimetic synthesis of the complex polypropionate derived natural product (±)-9,10-deoxytridachione. A previous study based on the elaboration of functionalised γ-pyrones allowed us to synthesise cyerc
- Rodriguez, Rapha?l,Adlington, Robert M.,Eade, Serena J.,Walter, Magnus W.,Baldwin, Jack E.,Moses, John E.
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- Synthesis of all four stereoisomers of 5-hydroxy-4-methyl-3-heptanone using plants and oyster mushrooms
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All four possible stereoisomers of 5-hydroxy-4-methyl-3-heptanone were synthesized from common achiral reagents using fast, straightforward organic synthesis, including the use of whole tissue of Daucus carota, Solanum melongena, and Pleurotus ostreatus.
- Bohman, Bj?rn,Unelius, C. Rikard
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- Chemoenzymatic Dynamic Kinetic Asymmetric Transformations of β-Hydroxyketones
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Herein we report on the development and application of chemoenzymatic Dynamic Kinetic Asymmetric Transformation (DYKAT) of α-substituted β-hydroxyketones (β-HKs), using Candida antartica lipase B (CALB) as transesterification catalyst and a ruthenium complex as epimerization catalyst. An operationally simple protocol allows for an efficient preparation of highly enantiomerically enriched α-substituted β-oxoacetates. The products were obtained in yields up to 95 % with good diastereomeric ratios.
- Hilker, Simon,Posevins, Daniels,Unelius, C. Rikard,B?ckvall, Jan-E.
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supporting information
p. 15623 - 15627
(2021/10/07)
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- Method for preparing 2-methyl-1,3-dicarbonyl derivative
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The invention discloses a method for preparing a 2-methyl-1,3-dicarbonyl derivative. A 1,3-dicarbonyl derivative serves as an initiator, raw materials are easy to obtain, and a great variety of raw materials are available. The product obtained through the method has high type diversity and can be used directly or used for other further reactions. Besides, only organic peroxides and a catalytic amount of inorganic copper salt are used, so that cost is low. According to the method, a reaction is conducted in air, reaction conditions are mild, pollution is small, reaction time is short, the yield of the target product is high, reaction operation and aftertreatment are easy, and the method is suitable for industrial production.
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Paragraph 0043
(2016/10/08)
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- Synthesis of valuable chiral intermediates by isolated ketoreductases: Application in the synthesis of α-alkyl-β-hydroxy ketones and 1,3-diols
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Regio- and stereoselective reductions of α-substituted 1,3-diketones to the corresponding β-keto alcohols or 1,3-diols by using commercially available ketoreductases (KREDs) are described. A number of α-monoalkyl- or dialkyl-substituted symmetrical as well as non-symmetrical diketones were reduced in high optical purities and chemical yields, in one or two enzymatic reduction steps. In most cases, two or even three out of the four possible diastereomers of α-alkyl-β-keto alcohols were synthesized by using different enzymes, and in two examples both ketones were reduced to the 1,3-diol. By replacing the α-alkyl substituent with the OAc group, 1-keto-2,3-diols, as well as 1,2,3-triols were synthesized in high optical purities. These enzymatic reactions provide a simple, highly stereoselective and quantitative method for the synthesis of different diastereomers of valuable chiral synthons from non-chiral, easily accessible 1,3-diketones.
- Kalaitzakis, Dimitris,Rozzell, J. David,Smonou, Ioulia,Kambourakis, Spiros
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p. 1958 - 1969
(2007/10/03)
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- Acylketene acetals in organic synthesis
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The preparation and reactivity of achiral and enantiomerically pure acylketene acetals are described. The key reactions of these substrates involve facile conjugate hydroboration and organolithium addition. Enantiomerically pure acylketene acetals were employed to generate a homochiral β-keto ketal through a highly diastereoselective lithium enolate quench. This β-ketal, which was also prepared through a desymmetrization ketalization reaction on a meso dione, was employed in the synthesis of the insect pheromone sitophilure.
- Eid Jr.,Konopelski
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p. 975 - 992
(2007/10/02)
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- Acylation of Ketone Silyl Enol Ethers with Acid Chlorides. Synthesis of 1,3-Diketones
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Trimethylsilyl enol ethers of ketones are acylated by a variety of acid chlorides in the presence of zinc chloride or antimony trichloride.The major product of this reaction is the 1,3-diketone resulting from C-acylation.Some O-acylation is observed in most cases.Yields of 1,3-diketones varied but were usually good to excellent.
- Tirpak, Robin E.,Rathke, Michael W.
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p. 5099 - 5102
(2007/10/02)
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