Esters-buliding-blocks

Wang, Tianli published the artcileRegiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives, Application In Synthesis of 10047-10-6, the main research area is aryl alkyl oxazolone butadienoate chiral phosphine regioselective enantioselective addition; disubstituted oxazolone stereoselective preparation ring opening; amino acid disubstituted stereoselective preparation; alkyl aryl oxazolone butadienoate chiral phosphine regioselective enantioselective addition; oxazolone disubstituted stereoselective preparation reduction; acetal lactol preparation.

Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective γ-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective γ-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronucleophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective γ-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts I (R = Et, Me, n-Pr,i-Pr, n-Bu, etc.; Ar = 4-MeOC6H4, Ph, 4-FC6H4) provided rapid access to optically enriched α,α-disubstituted α-amino acid derivatives, and the C-2-selective products II (R = Et, Me, n-Pr,i-Pr, n-Bu, etc.; Ar = Ph, 2-naphthyl, 1-naphthyl) led to facile synthesis of chiral N,O-acetals and γ-lactols. Theor. studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic oxazolide and the electrophilic phosphonium intermediate.

Journal of the American Chemical Society published new progress about Acetals Role: SPN (Synthetic Preparation), PREP (Preparation) (N,O-). 10047-10-6 belongs to class esters-buliding-blocks, name is Methyl 2-aminopentanoate hydrochloride, and the molecular formula is C6H14ClNO2, Application In Synthesis of 10047-10-6.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Niu, Yunwei published the artcileEvaluation of the perceptual interaction among ester aroma compounds in cherry wines by GC-MS, GC-O, odor threshold and sensory analysis: An insight at the molecular level, HPLC of Formula: 111-11-5, the main research area is wine ester aroma compound; Aroma intensity; Ester compounds; Olfactory threshold; Perceptual interaction.

The ester aroma profiles of five Chinese cherry wines and the perceptual interaction among esters were investigated in this study. 24 esters were identified by Gas chromatog.-olfactometry (GC-O) and Gas Chromatog.-Mass Spectrometer (GC-MS). According to addition/omission anal., seven volatile compounds among them were selected and studied using sensory profiling and multivariate statistic methods such as Principal Component Anal. (PCA). In sensory anal., a significant reduction of olfactory threshold for total aromatic reconstitution was induced by the addition among each of them in Feller’s additive model, which demonstrated their synergistic effects. The σ/τ plot showed that most of them were followed by a partial addition behavior. Furthermore, PCA indicated that the addition among each of them had a significant effect on fruity, floral, sweet and fermentation aroma intensity. Specifically, Et decanoate and Me salicylate at sub-threshold concentrations were also likely to contribute to overall aroma. The results of perceptual interaction were mainly influenced by chem. structure and mol. polarity.

Food Chemistry published new progress about Esters Role: ANT (Analyte), PRP (Properties), ANST (Analytical Study). 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, HPLC of Formula: 111-11-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Niu, Yunwei published the artcileEvaluation of the perceptual interaction among ester aroma compounds in cherry wines by GC-MS, GC-O, odor threshold and sensory analysis: An insight at the molecular level, Formula: C10H20O2, the main research area is wine ester aroma compound; Aroma intensity; Ester compounds; Olfactory threshold; Perceptual interaction.

The ester aroma profiles of five Chinese cherry wines and the perceptual interaction among esters were investigated in this study. 24 esters were identified by Gas chromatog.-olfactometry (GC-O) and Gas Chromatog.-Mass Spectrometer (GC-MS). According to addition/omission anal., seven volatile compounds among them were selected and studied using sensory profiling and multivariate statistic methods such as Principal Component Anal. (PCA). In sensory anal., a significant reduction of olfactory threshold for total aromatic reconstitution was induced by the addition among each of them in Feller’s additive model, which demonstrated their synergistic effects. The σ/τ plot showed that most of them were followed by a partial addition behavior. Furthermore, PCA indicated that the addition among each of them had a significant effect on fruity, floral, sweet and fermentation aroma intensity. Specifically, Et decanoate and Me salicylate at sub-threshold concentrations were also likely to contribute to overall aroma. The results of perceptual interaction were mainly influenced by chem. structure and mol. polarity.

Food Chemistry published new progress about Esters Role: ANT (Analyte), PRP (Properties), ANST (Analytical Study). 106-32-1 belongs to class esters-buliding-blocks, name is Ethyl octanoate, and the molecular formula is C10H20O2, Formula: C10H20O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Cagliero, Cecilia published the artcileCan the selectivity of phosphonium based ionic liquids be exploited as stationary phase for routine gas chromatography? A case study: The use of trihexyl(tetradecyl) phosphonium chloride in the flavor, fragrance and natural product fields, Category: esters-buliding-blocks, the main research area is phosphonium ionic liquid stationary phase GC; Flavors, fragrances and natural products; Gas chromatography; Ionic liquid stationary phases; Phosphonium based ionic liquids; Selectivity, efficiency and operative temperatures.

Room temperature ionic liquids (ILs) are well established stationary phases (SPs) for gas chromatog. (GC) in several fields of applications because of their unique and tunable selectivity, low vapor pressure and volatility, high thermal stability (over 300 °C), and good chromatog. properties. This study is focused on an IL based on a phosphonium derivative (trihexyl(tetradecyl)phosphonium chloride, [P+66614] [Cl-]), previously shown to be suitable as a gas chromatog. SP because of its unique selectivity. In particular, it aims to establish the operative conditions to apply [P+66614][Cl-] to routine anal. of samples containing medium to high volatility analytes with different polarity, organic functional groups and chem. structure. In the first part, the study critically evaluates long term [P+66614][Cl-] column stability and maximum allowable operating temperatures (MAOT). The relatively low MAOT (210 °C) requires the adoption of a dedicated approach for analytes eluting above this temperature based on a suitable combination of efficiency and selectivity, and column characteristics (length, inner diameter and film thickness) and operative conditions. The performance of [P+66614][Cl-] as a GC SP have been validated through the Grob test, a model mixture of 41 compounds of different polarity, structure, and with different organic functional groups in the flavor and fragrance field, a standard mixture of 37 fatty acid Me esters, some essential oils containing pairs or groups of compounds of different volatility critical to sep. in particular peppermint, thyme, oregano, sandalwood and frankincense. The above approach has produced highly satisfactory separations with all of the samples investigated.

Journal of Chromatography A published new progress about Essential oils Role: AMX (Analytical Matrix), ANST (Analytical Study). 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Munoz-Olasagasti, M. published the artcileElucidating the roles of acid site nature and strength in the direct conversion of levulinic acid into ethyl valerate: the case of Zr-modified beta zeolite-supported Pd catalysts, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is zirconium zeolite palladium catalyst levulinic acid one pot conversion; surface acidity.

The effects of the nature and strength of surface acid sites on the properties of the catalyst used for the one-pot conversion of levulinic acid to valeric biofuels have been investigated. The acid supports were prepared from a com. beta zeolite (HBEA) modified by partial substitution of Al by Zr atoms. This procedure enables changes in the nature and strength of the acidic sites of the starting zeolite. A constant amount of Pd (2 wt%) was incorporated on these acid supports by the incipient wetness impregnation method. These catalysts were tested in liquid phase reactions and the Pd/HBEA catalyst showed the best catalytic performance, achieving an 80% yield of valeric biofuel after 2 h of the reaction. The fresh catalysts were characterized by DRIFT spectroscopy using pyridine, CD3CN, and CO as probe mols. and by XRD to explain the differences in catalytic performance. The presence of strong Bronsted acid sites (BAS) was shown to be critical for reaching high Et valerate yields since the differences in catalytic behavior and the concentration of these acid sites parallel each other. Up to three types of Lewis acid sites (LAS) of different strengths were also identified. The spent catalyst underwent a simple calcination treatment at 773 K and this was adequate for the recovery of the surface acidity, but the reducibility of the Pd species was affected. This prevented complete recovery of catalytic activity.

Sustainable Energy & Fuels published new progress about Beta zeolites Role: CAT (Catalyst Use), PRP (Properties), USES (Uses). 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Recommanded Product: Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Mu, Yangxiu published the artcileAcid-catalyzed synthesis of pyrazolo[4,3-c]quinolines from (1H-pyrazol-5-yl)anilines and ethers via the cleavage of C-O bond, Recommanded Product: Benzyl acetate, the main research area is pyrazoloquinoline preparation; pyrazolylaniline ether cyclization carbon oxygen bond cleavage acid catalyst.

Acid-promoted the cyclization reaction for the synthesis of pyrazolo[4,3-c]quinolines from (1H-pyrazol-5-yl)anilines and ethers via the cleavage of C-O bond has been developed. This method exhibits the advantages of good functional group tolerance, simple reaction conditions and without addition of metal catalyst, providing novel products in moderate to good yields, which has potential applications in the organic, pharmaceutical chem.

Tetrahedron published new progress about Anilines Role: RCT (Reactant), RACT (Reactant or Reagent) (pyrazolyl). 140-11-4 belongs to class esters-buliding-blocks, name is Benzyl acetate, and the molecular formula is C9H10O2, Recommanded Product: Benzyl acetate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Floyd, James G. published the artcileLocating and quantifying carbon steel corrosion rates linked to fungal B20 biodiesel degradation, Safety of Methyl docosanoate, the main research area is carbon steel biodiesel corrosion rate Paecilomyces.

Fungi that degrade B20 biodiesel in storage tanks have also been linked to microbiol. influenced corrosion (MIC). A member of the filamentous fungal genus Paecilomyces and a yeast from the genus Wickerhamomyces were isolated from heavily contaminated B20 storage tanks from multiple Air Force bases. Although these taxa were linked to microbiol. influenced corrosion in situ, precise measurement of their corrosion rates and pitting severity on carbon steel was not available. In the experiments described here, we directly link fungal growth on B20 biodiesel to higher corrosion rates and pitting corrosion of carbon steel under controlled conditions. When these fungi were growing solely on B20 biodiesel for carbon and energy, consumption of FAME and n-alkanes was observed The corrosion rates for both fungi were highest at the interface between the B20 biodiesel and the aqueous medium, where they acidified the medium and produced deeper pits than abiotic controls. Paecilomyces produced the most corrosion of carbon steel and produced the greatest pitting damage. This study characterizes and quantifies the corrosion of carbon steel by fungi that are common in fouled B20 biodiesel through their metabolism of the fuel, providing valuable insight for assessing MIC associated with storing and dispensing B20 biodiesel. Biodiesel is widely used across the United States and worldwide, blended with ultra-low-sulfur diesel in various concentrations In this study, we were able to demonstrate that the filamentous fungus Paecilomyces AF001 and the yeast Wickerhamomyces SE3 were able to degrade fatty acid Me esters and alkanes in biodiesel, causing increases in acidity. Both fungi also accelerated the corrosion of carbon steel, especially at the interface of the fuel and water, where their biofilms were located. This research provides controlled, quantified measurements and the localization of microbiol. influenced corrosion caused by common fungal contaminants in biodiesel fuels.

Applied and Environmental Microbiology published new progress about Alkanes Role: TEM (Technical or Engineered Material Use), USES (Uses). 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, Safety of Methyl docosanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Al-Gharibeh, Elyasa published the artcileOxidation kinetics of methyl decanoate in a motored engine, Computed Properties of 110-42-9, the main research area is methyl decanoate motored engine oxidation kinetics.

Low-temperature oxidation of Me decanoate was exptl. investigated in a motored engine. The engine was operated in a premixed mode at a fixed speed of 700 rpm and an intake temperature of 125°C. Compression ratio was varied between 5.5 and 9.0 for an equivalence ratio of 0.25. The study analyzes heat release and stable species concentrations in the oxidation products at each studied compression ratio. A gas chromatograph-mass spectrometer was used to identify and quantify the composition of the exhaust gas. More than sixty stable intermediate species were detected. Quant. concentration measurements were carried out for selected alkenes, aldehydes, ketones, ethers, and alcs. A Fourier transform IR spectrometer was used to detect and quantify carbon monoxide and dioxide. The oxidation process shares features in common with alkane oxidation, with differences related to Me ester intermediates formation specific to Me decanoate oxidation Specifically, the unsaturated ester Me prop-2-enoate was generated in considerable amounts The heat release and speciation trends show two-stage ignition and neg. temperature coefficient features. The exptl. data are also compared to numerical results calculated based on an existing reaction mechanism for Me decanoate.

Fuel published new progress about Acetoxymethyl esters Role: NUU (Other Use, Unclassified), USES (Uses). 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Computed Properties of 110-42-9.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Wei, Duo published the artcileManganese and rhenium-catalyzed selective reduction of esters to aldehydes with hydrosilanes, Quality Control of 110-42-9, the main research area is aldehyde preparation photochem; carboxylic ester reduction manganese rhenium catalyst; triethylsilane carboxylic ester hydrosilylation; alkyl silyl acetal preparation chemoselective photochem.

The selective reduction of esters RC(O)OR1 [R = (4-chlorophenyl)methyl, naphthalen-2-ylmethyl, nonyl, etc.; R1 = Me, Et] to aldehydes RC(O)H (I), via the formation of stable alkyl silyl acetals RCH(OSi(C2H5)3)OR1 (II), for the first time, was achieved with both manganese, -Mn2(CO)10- and rhenium -Re2(CO)10- catalysts in the presence of triethylsilane as reductant. These two methods provide a direct access to a large variety of aliphatic and aromatic alkyl silyl acetals II and to the corresponding aldehydes I upon hydrolysis. The reactions proceeded in excellent yields and high selectivity at room temperature under photo-irradiation conditions (LED, 365 nm, 40 W, 9 h).

Chemical Communications (Cambridge, United Kingdom) published new progress about Acetals Role: SPN (Synthetic Preparation), PREP (Preparation) (silyl). 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Quality Control of 110-42-9.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Liu, Xiaoyan published the artcileEffect of ageing process on carcinogen ethyl carbamate (EC), its main precursors and aroma compound variation in Hakka Huangjiu produced in southern China, Related Products of esters-buliding-blocks, the main research area is hakka huangjiu ethyl carbamate myristate citrulline aging temperature China.

Summary : Wine ageing is of great importance to the quality and organoleptic properties of Huangjiu. The aim of the present work was to investigate the effect of ageing temperature on the content changes in Et carbamate (EC) and its precursors including citrulline, arginine, ornithine and urea in Hakka Huangjiu. Aroma compound changes were also detected using headspace solid-phase microextraction coupled with gas chromatog. spectrometry. Results indicated that with the increase in ageing temperature, citrulline and EC concentrations increased, whereas arginine and ornithine concentrations decreased. Urea was decreased slightly from 4 to 20 °C while increased at 37 °C. Pearson test demonstrated that ageing temperature had significant correlation with EC and arginine. The concentrations of aroma compounds, especially esters, alcs., acids and heterocyclic compounds were different in different ageing temperatures Ageing temperature of Hakka Huangjiu was suggested setting in a lower temperature as for strictly controlling contents of urea and citrulline, as well as EC.

International Journal of Food Science and Technology published new progress about pH Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 41114-00-5 belongs to class esters-buliding-blocks, name is Ethyl pentadecanoate, and the molecular formula is C17H34O2, Related Products of esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics