19041-15-7Relevant academic research and scientific papers
Direct asymmetric reduction of levulinic acid to gamma-valerolactone: synthesis of a chiral platform molecule
Tukacs, József M.,Fridrich, Bálint,Dibó, Gábor,Székely, Edit,Mika, László T.
, p. 5189 - 5195 (2015)
Levulinic acid was directly converted to optically active (S)-gamma-valerolactone, a proposed biomass-based chiral platform molecule. By using a SEGPHOS ligand-modified ruthenium catalyst in methanol as a co-solvent, eventually, 100% chemoselectivity, and 82% enantioselectivity were achieved. The effect of the catalyst composition and reaction parameters on the activity and selectivity was investigated in detail. The conversion of a "real" biomass derived levulinic acid to optically active GVL without decreasing the enantioselectivity was also demonstrated.
Dynamic kinetic resolution of γ-hydroxy acid derivatives
Runmo, Ann-Britt L,Pàmies, Oscar,Faber, Kurt,B?ckvall, Jan-E
, p. 2983 - 2986 (2002)
Enzymatic resolution and dynamic kinetic resolution of γ-hydroxy acid derivatives 1 have been investigated. Efficient kinetic resolution was obtained using Pseudomonas cepacia lipase in toluene (E value ~400). The combination of enzymatic kinetic resoluti
Facile Synthesis of Optically-Active Γ-Valerolactone from Levulinic Acid and Its Esters Using a Heterogeneous Enantio-Selective Catalyst
Osawa, Tsutomu,Tanabe, Yuya
, p. 824 - 830 (2018)
Abstract: Optically-active γ-valerolactone was synthesized by the enantio-selective hydrogenations of levulinic acid and its esters. A tartaric acid-NaBr-modified nickel catalyst produced the optically-active γ-valerolactone with a 60% enantiomeric excess (ee), almost quantitative conversion and chemoselectivity. The synthesis of the optically-active γ-valerolactone using the enantio-selective heterogeneous catalyst would be promising for the large-scale industrial production from levulinic acid and its esters, which can be obtained by the acid-catalyzed dehydration of cellulosic fraction of biomass. Graphical Abstract: [Figure not available: see fulltext.].
The role of protic solvent in asymmetric hydrogenation of methyl levulinate in the presence of a ruthenium-containing catalyst
Starodubtseva,Turova,Vinogradov,Gorshkova,Ferapontov
, p. 552 - 554 (2007)
A comparative study of asymmetric hydrogenation and deuteration of methyl levulinate catalyzed by the RuII-(S)-BINAP-HCl system (BINAP is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) in MeOH and MeOD was carried out. The results obtained suggest an important role of the protic solvent in the formation of catalytically active ruthenium complexes.
Allergenic α-Methylene-γ-butyrolactones. Stereospecific Syntheses of (+)- and (-)-γ-Methyl-α-methylene-γ-butyrolactones. A Study of the Specificity of (+) and (-) Enantiomers in Inducing Allergic Contact Dermatitis
Barbier, Pierre,Benezra, Claude
, p. 943 - 946 (1982)
The enantiomers of γ-methyl-α-methylene-γ-butyrolactone have been prepared stereospecifically from (R)- and (S)-glutamic acid.Three groups of guinea pigs have been sensitized (Feund complete adjuvant technique) to the (+)-isomer, the (-)-isomer, and the (+/-)-mixture.The animals have been tested with each of the enantiomers and with a mixture of the compounds.Only the (-) enantiomer showed some specificity: guinea pigs sensitized to this enantiomer react weakly to the other compound; in turn, animals sensitized to the (+) enantiomer react similarly to both antipodes.Interestingly, reaction to the (+/-) mixture in each group of guinea pigs was the sum of skin responses to the individual enantiomer.These results should be contrasted with sensitization to (+)- and (-)-frullanolides, sesquiterpene lactones for which strong stereospecificity was observed.
Access to lactone building blocks via horse liver alcohol dehydrogenase-catalyzed oxidative lactonization
Kara, Selin,Spickermann, Dominik,Schrittwieser, Joerg H.,Weckbecker, Andrea,Leggewie, Christian,Arends, Isabel W. C. E.,Hollmann, Frank
, p. 2436 - 2439 (2013)
The oxidative lactonization of 1,4-, 1,5-, and 1,6-diols using horse liver alcohol dehydrogenase (HLADH) is reported. Molecular oxygen was used as terminal electron acceptor by utilization of the laccase-mediator concept to regenerate the oxidized nicotinamide cofactor and producing water as sole byproduct. Spontaneous hydrolysis of the lactone products was identified as a major limiting factor toward preparative application of the system, which can be alleviated by using a two liquid phase approach to extracting the product into an organic solvent.
Enantioselective, electrocatalytic lactonization of methyl-substituted diols on a TEMPO-modified graphite felt electrode in the presence of (-)-sparteine
Yanagisawa, Yoshinori,Kashiwagi, Yoshitomo,Kurashima, Futoshi,Anzai, Jun-Ichi,Osa, Tetsuo,Bobbitt, James M.
, p. 1043 - 1044 (1996)
A TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxyl)-modified graphite felt electrode afforded enantioselective, electrocatalytic lactonized products of (S)-(-)-3,4,5,6-tetrahydro-4-melhyl-2-pyranone, (S)-(-)-4,5-dihydro-4-methyl-2(3H)-furanone and (S)-(-)-4,5-dihydro-5-methyl-2(3H)-furanone from 3-methylpentane-1,5-diol, (S)-(-)-2-methylbutane-1,4-diol and racemic pentane-1,4-diol, respectively, in enantiomeric excess more than 95%, in the presence of (-)-sparteine in acetonitrile. The current efficiency and isolated yield of former two lactones were more than 90%.
Synthesis of (5S)-5-methylfuran-2(5H)-one and its dihydro derivative
Loza,Vostrikov,Miftakhov
, p. 1804 - 1806 (2008)
(5S)-5-Methylfuran-2(5H)-one and (5S)-5-methyltetrahydrofuran-2-one were synthesized starting from L-lactic acid ethyl ester.
Kinetic resolution and chemoenzymatic dynamic kinetic resolution of functionalized γ-hydroxy amides
Fransson, Ann-Britt L.,Boren, Linnea,Pamies, Oscar,Baeckvall, Jan-E.
, p. 2582 - 2587 (2005)
(Chemical Equation Presented) An efficient kinetic resolution of racemic γ-hydroxy amides 1 was performed via Pseudomas cepacia lipase (PS-C)-catalyzed transesterification. The enzyme PS-C tolerates both variation in the chain length and different functionalities giving good to high enantioselectivity (E values of up to >250). The combination of enzymatic kinetic resolution with a ruthenium-catalyzed racemization led to a dynamic kinetic resolution. The use of 2,4-dimethyl-3-pentanol as a hydrogen source to suppress ketone formation in the dynamic kinetic resolution yields the corresponding acetates in good yield and good to high enantioselectivity (ee's up to 98%). The synthetic utility of this procedure was illustrated by the practical synthesis of the versatile intermediate γ-lactone (R)-5-methyltetrahydrofuran-2-one.
Asymmetric cyclization of unsaturated alcohols and carboxylic acids with camphor-based selenium electrophiles
Back, Thomas G.,Dyck, Brian P.
, p. 2567 - 2568 (1996)
The diastereoselective cyclization of a series of unsaturated alcohols and carboxylic acids was achieved with chiral camphor-based selenenyl chlorides, of which the spirooxazolidinone 3c proved the most effective.
