24915-95-5Relevant academic research and scientific papers
The effect of absorbing resins on substrate concentration and enantiomeric excess in yeast reduction
D'Arrigo, Paola,Fantoni, Giuseppe Pedrocchi,Servi, Stefano,Strini, Alberto
, p. 2375 - 2379 (1997)
The correlation between the enantiomeric excess (e.e.) of the (S)-(+)-ethyl-3-hydroxybutanoate 2, obtained in the baker's yeast reduction of ethyl acetoacetate 1, and the concentration of the substrates in the fermentation mixture has been studied by the use of two different techniques (absorbing resins and organic solvents) The presence of resins undoubtedly influences the enantiomeric excess of the product.
Einfache Umwandlung von (-)-(R)-3-Hydroxybuttersaeure in das (+)-(S)-Enantiomere und dessen Lacton (-)-(S)-4-Methyloxethan-2-on
Griesbeck, Axel,Seebach, Dieter
, p. 1320 - 1325 (1987)
Condensation of (R)-3-hydroxybutanoic acid (1) with ethyl orthoacetate gives a 2-ethoxy-substituted 1,3-dioxanone 2 which is thermally labile: at ca. 100 deg C, two competing processes commence, one leading to ethyl (R)-3-acetoxybutanoate (3), the other one - with complete inversion of configuration - to the (S)-4-methyloxetan-2-one (4) and ethyl acetate.These can be readily separated by fractional distillation.Thus, enantiomerically pure (S)-3-hydroxybutanoic acid (ent-1) and l-2-alkyl-3-hydroxybutanoic acid derivatives (such as 6 and 8) become available from the biopolymer PHB, the precursor to the acid 1.
The use of liquefied petroleum gas (LPG) as a solvent for yeast reactions
Johns, Melanie K.,Smallridge, Andrew J.,Trewhella, Maurie A.
, p. 4261 - 4262 (2001)
The yeast mediated reduction of ethyl acetoacetate to ethyl (S)-3-hydroxy butyrate proceeds with good yield and high enantioselectivity in liquefied petroleum gas (LPG). It was found that slightly more water (2 ml/g yeast) and more yeast (1.6 g/mmol substrate) were required to effect complete conversion than was the case with more conventional organic solvents, such as petroleum spirit.
The effect of particle size and ligand configuration on the asymmetric catalytic properties of proline-functionalized Pt-nanoparticles
Schrader, Imke,Neumann, Sarah,Himstedt, Rieke,Zana, Alessandro,Warneke, Jonas,Kunz, Sebastian
, p. 16221 - 16224 (2015)
The effect of particle size on the asymmetric catalytic properties of supported ligand-functionalized nanoparticles (NPs) was investigated for the first time and found to alter significantly the activity but surprisingly not the stereoselectivity. These results suggest that the stereoselectivity of these complex systems is primarily determined by the ligand-reactant interaction, whereas the activity is determined by the particle size.
Enantio-differentiating hydrogenation of alkyl 3-oxobutanoates over tartaric acid-modified Ni catalyst: Enthalpy-entropy compensation effect as a tool for elucidating mechanistic features
Osawa, Tsutomu,Wakasugi, Masahiro,Kizawa, Tomoko,Borovkov, Victor,Inoue, Yoshihisa
, p. 131 - 136 (2018)
The enantio-differentiating hydrogenations of a series of alkyl 3-oxobutanoates were carried out at the temperatures ranging from 333 to 393 K over the (R,R)-tartaric acid-modified Ni catalyst prepared from commercially available Ni powder to achieve high enantiomeric excesses of 91-94%. It was demonstrated that the enantio-selectivity was not a simple function of the reaction temperature, being enhanced in the low temperature region to reach a maximum at 363–373 K and then decreased at higher temperatures. Nevertheless, all the differential enthalpies and entropies of activation calculated from the enantiomer ratios in the low and high temperature regions compensated with each other, indicating the same enantio-differentiation mechanism over the entire temperature range. A plausible enantio-differentiation mechanism explaining the effects of hydrogenation temperature on the enantio-selectivity is proposed.
A simple enantioselective synthesis of γ-valerolactone
O'Neill,Lindell,Simpson,Willis
, p. 117 - 118 (1994)
The readily available biopolymer, poly-(R)-3-hydroxybutyrate was converted to (R)-(+)-γ-valerolactone in 32% overall yield in a simple 4 stage procedure.
On the microbial reduction of ethyl α-methylacetoacetate
Ramos, Aline de Souza,Ribeiro, Joyce Benzaquem,Vazquez, Leonardo,Fiaux, Sorele Batista,Leite, Selma Gomes Ferreira,Cruz, Renata de Andrade,Ramos, Maria da Conceicao Klaus V.,Neto, Francisco Radler de Aquino,Antunes, Octavio A.C.
, p. 559 - 561 (2009)
In the present work several microorganisms were screened in the reduction of methyl and ethyl acetoacetates. Good to excellent ees were obtained with up to quantitative substrate conversions. These microorganisms were also tested in the reduction of ethyl α-methylacetoacetate with good des and excellent ees. It was noticed that Kluyveromyces marxianus and Trichoderma harzianum were found to lead to products of opposite configuration with the use of methyl or ethyl acetoacetates, which is a very unusual finding.
Whole-cell biocatalysis in deep-eutectic-solvents/aqueous mixtures
Maugeri, Zaira,Dominguez De Maria, Pablo
, p. 1535 - 1537 (2014)
Whole-cell biocatalysis with the use of baker's yeast is demonstrated in different mixtures of water with deep eutectic solvents (DESs; choline chloride/glycerol, 1:2 mol/mol). Enantioselective ketone reduction is observed for long reaction times (>200 h), which suggests that the whole cells remain stable in these neoteric solvents. By changing the proportion of the DES added, a complete inversion of enantioselectivity is observed, from approximately 95 % enantiomeric excess (ee) (S) in pure water to approximately 95 % ee (R) in the pure DES. Presumably, some (S)-oxidoreductases present in baker's yeast are inhibited by DESs. DESpicably good: Whole-cell biocatalysis with the use of baker's yeast is demonstrated in different mixtures of water with deep eutectic solvents (DESs). Enantioselective ketone reduction is observed for long reaction times (>200 h), which suggests that the whole cells remain stable in these neoteric solvents. By changing the proportion of the DES added, a complete inversion of enantioselectivity is observed.
Formation of the (R)- and (S)-Enantiomers of Ethyl 3-Hydroxybutanoate and of 1-(1,3-Dithian-2-yl)-2-hydroxypropane by Microbial Reduction
Bernardi, Rosanna,Cardillo, Rosanna,Ghiringhelli, Dario
, p. 460 - 461 (1984)
The (R) and (S) enantiomers of 3-hydroxybutanoate and 1-(1,3-dithian-2-yl)-2-hydroxypropane are obtained from ethyl 3-oxobutanoate (1a) and 1-(1,3-dithian-2-yl)-2-oxopropane (1b), respectively, using growing cultures from different strains of Geotrichum candidum and Aspergillus niger.
Note on Biotransformations with Halobacterium halobium: Reduction of Ethyl 3-Oxobutanoate and Hydrolysis of Ethyl 3-Hydroxybutanoate. Cooperative Effects of Reductase and Hydrolase
Ehrler, Juerg von,Seebach, Dieter
, p. 793 - 799 (1989)
The archaebacterium Halobacterium halobium, growing in saturated NaCl solution, is tested for its ability to achieve biotransformations.We found that this microorganism does accept only a small veriety of compounds as substrates.Ethyl acetoacetate (1) is reduced to ethyl (S)-3-hydroxybutanoate (2) of optical purity of 40-76 percent, but in low chemical yields.The reduction is accompanied by hydrolysis of the hydroxy-ester to 3-hydroxybutanoic acid (3).Hydrolysis of rac-ester 2 by Halobacterium halobium gives (R)-2 of optical purity of up to 88 percent, depending upon reaction time, together with the almost racemic hydroxy-acid 3, both in low chemical yields.Hopes that the 'extremist' Halobacterium halobium would be able to effect unique conversions were not fulfilled.
