Tag: M.W:100-200

13031-04-4, Chemistry is the experimental science by definition. We want to make observations to prove hypothesis. For this purpose, we perform experiments in the lab. 13031-04-4, Name is 4,4-Dimethyldihydrofuran-2,3-dione,introducing its new discovery.

Novel Enzymatic Production of D-(-)-Pantoyl Lactone through the Stereospecific Reduction of Ketopantoic Acid

The high yield stereoselective reduction of ketopantoic acid to D-(-)-pantoic acid with microbial cells as a catalyst is described .High activity was found in several bacteria belonging to the genus Agrobacterium.On incubation with a soil isolate, Agrobacterium sp.S-246, the yield of D-(-)-pantoic acid reached 119 mg/ml, with high molar conversion (90percent) and high stereoselectivity (>98percent enantiomeric excess).Ketopantoic acid reductase (EC 1.1.1.169) was suggested to be the enzyme responsible for this conversion.

We¡¯ll also look at important developments in the pharmaceutical industry because understanding organic chemistry is important in understanding health, medicine, the role of 13031-04-4, and how the biochemistry of the body works.13031-04-4

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

Chemistry is the science of change. But why do chemical reactions take place? Why do chemicals react with each other? The answer is in thermodynamics and kinetics.In a document type is Article, the author is Fleck, Martin and a compound is mentioned, 4971-56-6, Furan-2,4(3H,5H)-dione, introducing its new discovery. 4971-56-6

Total synthesis of punctaporonin c by a regio-and stereoselective [2+2]-photocycloaddition

The unique sesquiterpene punctaporonin C was synthesized starting from commercially available 7-tertbutoxynorbornadiene in a linear sequence of 29 steps and with an overall yield of 0.65%. Key step of the synthesis was an intramolecular [2+2]-photocycloaddition, in which the two vinylic double bonds in a 1,3-divinyl-2-cyclopentyl tetronate were differentiated by reaction with the photoexcited tetronate. The reaction gave regio-and diastereoselective access to the tricyclic core skeleton of punctaporonin C in 63% yield. Additional studies related to the tetronate [2 + 2]-photocycloaddition revealed that even diastereotopic vinylic double bonds in a 1,3-divinyl-2cyclopentyl tetronate can be differentiated (d.r. up to 78:22). In the further course of the total synthesis the complete tetracyclic oxatetracyclo[6.3.2.0 1.4.05,12]tridecane skeleton of punctaporonin C was established by an intramolecular aldol reaction, closing a seven-membered oxepane ring. The nucleophilic methyl ketone employed in this step was generated by Wacker oxidation of the vinylic double bond, which was not involved in the [2 + 2]photocycloaddition. Several reactions employed in the synthetic sequence required adaptation to the rigid skeleton of punctaporonin C, for example, the reduction of a mesylate, the alkylation of a cyclobutane carboxylate, or the methyl addition to a prostereogenic carbonyl group.

Interested yet? Keep reading other articles of 1532-97-4!, 4971-56-6

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

13031-04-4, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 13031-04-4, Name is 4,4-Dimethyldihydrofuran-2,3-dione, molecular formula is C6H8O3. In a Article, authors is Morimoto, Toshiaki£¬once mentioned of 13031-04-4

CATALYTIC ASYMMETRIC HYDROGENATION WITH RHODIUM COMPLEXES OF IMPROVED DIOPS BEARING PARA-DIMETHYLAMINO GROUP ON THE BASIS OF OUR DESIGNING CONCEPT

Unsymmetrized and symmetrized DIOP analogues bearing para-dimethylamino group have been synthesized to prove the general utility of our designing concept for developing highly effective catalysts.Their rhodium complexes have been shown to be much more effective in the asymmetric hydrogenations than that of DIOP.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. 13031-04-4, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 13031-04-4, in my other articles.

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

22530-98-9, Because a catalyst decreases the height of the energy barrier, its presence increases the reaction rates of both the forward and the reverse reactions by the same amount.22530-98-9, Name is 4-Benzyldihydrofuran-2(3H)-one, molecular formula is C11H12O2. In a article£¬once mentioned of 22530-98-9

Tetramethylethylene diamine/trimethylsilyl chloride mediated addition of benzyl copper reagents to alpha,beta-unsaturated esters

Several benzylic copper reagents, benzylcopper, 4-methoxybenzylcopper and 1-phenylethylcopper, facilitate the conjugate addition of the corresponding benzyl ligands to alpha,beta-enoates in the presence of tetramethylethylene diamine and trimethylsilyl chloride in high yields.

A reaction mechanism is the microscopic path by which reactants are transformed into products. Each step is an elementary reaction. 22530-98-9, In my other articles, you can also check out more blogs about 22530-98-9

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

4971-56-6, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 4971-56-6, Name is Furan-2,4(3H,5H)-dione, molecular formula is C4H4O3. In a Article, authors is Murphy, Paul V.£¬once mentioned of 4971-56-6

The reactions of diazo compounds with lactones. Part 2. The reaction of cyclic 2-diazo-1,3-dicarbonyl compounds with diketene: Benzofuran formation

Cyclic 2-diazo-1,3-dicarbonyl compounds react with diketene in the presence of rhodium(II) salts to give benzofurans as the major isolated products. The formation of intermediate products with exocyclic double bonds which isomerise to benzofurans provides support for the proposed mechanism which involves initial formation of a dioxaspirooctenone by a formal dipolar cycloaddition reaction of a carbenoid to the exocyclic double bond of diketene followed by the loss of carbon dioxide. Acyclic 2-diazo-1,3-dicarbonyl compounds give furans in poor yield.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. 4971-56-6, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 4971-56-6, in my other articles.

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

4971-56-6, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 4971-56-6, Name is Furan-2,4(3H,5H)-dione, molecular formula is C4H4O3. In a Article, authors is Nejadshafiee, Vajihe£¬once mentioned of 4971-56-6

Sonochemical synthesis of library benzodiazepines using highly efficient molecular ionic liquid supported on Fe-MCM-41 nanocomposites as a recyclable catalyst

In this study, library substituted benzodiazepines was synthesized using molecular ionic liquid supported on Fe-MCM-41 nanocomposites (Fe-MCM-41-IL). This protocol using ultrasound provided advantages such as rapid, clean conversion and simplicity in experimental setup that led to rapid generation of benzodiazepines under mild condition. The catalyst can be easily isolated by using an external magnetic field and reused in the next reaction up to six cycles without obvious activity decreasing.

Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.4971-56-6. In my other articles, you can also check out more blogs about 4971-56-6

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

637-64-9, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 637-64-9, Name is Tetrahydrofurfuryl Acetate, molecular formula is C7H12O3. In a Article, authors is Murnieks, Raimonds£¬once mentioned of 637-64-9

Hydrotreating of wheat straw in toluene and ethanol

In the present work, wheat straw was hydroliquefied at a temperature of 300C for 4h in ethanol or toluene in order to obtain bio-components which are useful for fuel purposes. The experiments were performed in a 100mL batch reactor under hydrogen pressure of 70bar. Typically, 2g of straw and 0.1g of catalyst (66%Ni/SiO2-Al2O3) were dispersed in 15g of solvent. The main compounds of the oil produced during the liquefaction of hemicellulose, cellulose and lignin of wheat straw in both solvents are: tetrahydrofuran-2-methanol, 1,2-butanediol and butyrolactone. Besides the mentioned compounds, ethanol favoured the decomposition of bigger molecules to short-chain alcohols such as 1-butanol, 1,2-propanediol and 1,2-ethanediol. Toluene contributes to the production of furans and other cyclic compounds. The light fractions distilled together with the solvent also contain the following: 1-propanol, 2-methyl-cyclopentanone, acetic acid and ethyl acetate.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. 637-64-9, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 637-64-9, in my other articles.

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

105-21-5, Because a catalyst decreases the height of the energy barrier, its presence increases the reaction rates of both the forward and the reverse reactions by the same amount.105-21-5, Name is Gamma-heptalactone, molecular formula is C7H12O2. In a article£¬once mentioned of 105-21-5

Capillary gas chromatographic properties of three new mono-ester permethylated beta-cyclodextrin derivatives

2I-O-Methoxycarbonylmethyl-2II-VII,3 I-VII,6I-VII-eicosa-O-methyl-cyclodextrin (20Me/P2OCH 2COOMe), 6I-O-methoxycarbonylmethyl-2I-VII, 3I-VII,6II-VII-eicosa-O-methyl-cyclodextrin (20Me/P6OCH2COOMe), 6I-O-methoxycarbonyl-6 I-deoxy-2I-VII,3I-VII,6II-VII- eicosa-O-methyl-cyclodextrin (20Me/P6COOMe) have been evaluated as chiral stationary phases (CSPs) for capillary gas chromatography. General chromatographic properties of the corresponding columns have been investigated in terms of efficiency, polarity and inertness. More than 60 solutes have been used for studying their enantioselectivity by comparison with permethylated beta-cyclodextrin as a reference. Similar enantioseparation ability was established for the four studied CSPs, the 20Me/P2OCH2COOMe exhibiting in most cases a better enantioselectivity than the other selectors.

105-21-5, Interested yet? Read on for other articles about 105-21-5!

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

13031-04-4, The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.13031-04-4, Name is 4,4-Dimethyldihydrofuran-2,3-dione, molecular formula is C6H8O3. In a Article, authors is Schuerch£¬once mentioned of 13031-04-4

Enantioselective Hydrogenation of Ketopantolactone: Effect of Stereospecific Product Crystallization during Reaction

The hydrogenation of ketopantolactone over cinchonidine-modified Pt/alumina has been reinvestigated, focussing on the misleading effect of stereospecific product crystallization during reaction at medium to high conversions. The appropriate choice of reaction conditions afforded 91.6 ¡À 0.5% ee to R-(-)-pantolactone.

A reaction mechanism is the microscopic path by which reactants are transformed into products. Each step is an elementary reaction. In my other articles, you can also check out more blogs about 13031-04-4

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem

In homogeneous catalysis, the catalyst is in the same phase as the reactant. The number of collisions between reactants and catalyst is at a maximum.In a patent, 13031-04-4, name is 4,4-Dimethyldihydrofuran-2,3-dione, introducing its new discovery. 13031-04-4

MANUFACTURE OF KETOPANTOLACTONE

A process for the oxidation of pantolactone to ketopantolactone comprises carrying out the oxidation with a periodate in the presence of a ruthenium catalyst, in an aqueous solvent system and in a microwave field. Ketopantolactone is a key intermediate in the manufacture of pantothenic acid, the latter being a member of the B complex vitamins and a constituent of coenzyme A. Asymmetric hydrogenation of ketopantolactone yields (D)(-)-pantolactone, from which pantothenic acid can then be manufactured.

Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.13031-04-4, you can also check out more blogs about13031-04-4

Reference£º
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem