Tag: M.W=100-150

Zhu, Yasheng published the artcileEnantioselective Construction of Single and Vicinal All-Carbon Quaternary Stereocenters through Ion Pair Catalyzed 1,6-Conjugate Addition, Formula: C6H8O3, the publication is Organic Letters (2021), 23(18), 7248-7253, database is CAplus and MEDLINE.

An asym. 1,6-conjugate addition to presynthesized δ-aryl-δ-cyano disubstituted para-quinone methides I (R = H, 3-Me, 3-bromo; Ar = Ph, 4-methylphenyl, 2-naphthyl, etc.) through bifunctional phosphonium-amide promoted ion pair catalysis for acyclic all-carbon quaternary stereocenter construction has been described. Both acyclic and cyclic 1,3-dicarbonyls CH₂(C(O)OR¹)₂ (R¹ = Ph, 2-methylphenyl, benzyl, etc.)/II (R² = Me, Et, Bu, allyl) participate in asym. alkylation reaction, furnishing a wide array of diarylmethanes bearing a single acyclic or vicinal cyclic and acyclic quaternary carbon stereocenters III/IV in high efficiency with excellent stereoselectivity. Computational studies elucidate the origin of enantioselectivity.

Organic Letters published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C38H74Cl2N2O4, Formula: C6H8O3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Li, Z. W. published the artcileAnalysis of volatile aroma compounds from five types of Fenghuang Dancong tea using headspace-solid phase microextraction combined with GC-MS and GC-olfactometry, Related Products of esters-buliding-blocks, the publication is International Food Research Journal (2021), 28(3), 612-626, database is CAplus.

The present work describes the relationship between volatile aroma components and flavors of Fenghuang Dancong tea. Volatile aroma components of five types of Fenghuang Dancong tea namely Baxian, Milanxiang, Yulanxiang, Guihuaxiang, and Yinhuaxiang were extracted by headspace solid-phase microextraction (HS-SPME), then analyzed by gas chromatog.- mass spectrometry (GC-MS) technique and gas chromatog. olfactometry (GC-O) techniques. The GC-MS results showed that a total of 116 volatile components were detected, among which 21 (including alcs., esters, olefins, aldehydes, ketones, and alkanes) were commonly detected in all types of tea. Based on GC-O anal., 26 active ingredients that mainly contribute to grassy, sweet, floral, fruity, woody, and honey aromas were detected. Among these ingredients, four compounds including linalool oxide I, linalool, nerol, and neroli, which give floral, sweet, and honey aromas were abundant (with high aroma intensity) in all five types of tea. This suggests that these compounds are the main components contributing to the unique aroma of Fenghuang Dancong tea.

International Food Research Journal published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, Related Products of esters-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Cao, Shi-Xuan published the artcileMagnetic nanoparticles supported cinchona alkaloids for asymmetric Michael addition reaction of 1,3-dicarbonyls and maleimides, Category: esters-buliding-blocks, the publication is Chinese Chemical Letters (2018), 29(1), 201-204, database is CAplus.

Magnetic nanoparticles Fe₃O₄@SiO₂ supported cinchona alkaloids (quinine and quinidine) were successfully synthesized as magnetically recoverable organocatalysts and characterized by FT-IR, XPS, SEM measurements, and elemental anal. Their catalytic activity and stereoselectivity were preliminarily evaluated in the asym. Michael addition reaction of 1,3-dicarbonyl compounds and maleimides to afford 3-(2-oxocyclopentyl)pyrrolidine-2,5-dione derivatives I [R = H, Me, Bn, etc.; R¹ = C(O)Me, CO₂Et, CO₂Me], 3-[3-acetyl-2-oxo-tetrahydrofuran-3-yl]-1-benzyl-pyrrolidine-2,5-dione and ethyl-2-[1-benzyl-2,5-dioxo-pyrrolidin-3-yl]-3-oxo-butanoate. The supported quinine catalyst exhibited good catalytic efficiency and modest to high enantioselectivity. The magnetic recoverability and recyclability of the catalyst were also examined

Chinese Chemical Letters published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, Category: esters-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Zhou, You published the artcileI₂-Promoted site-selective C-C bond cleavage of aryl methyl ketones as C1 synthons for constructing 5-acyl-1H-pyrazolo[3,4-b]pyridines, COA of Formula: C7H13NO2, the publication is Organic Chemistry Frontiers (2022), 9(16), 4416-4420, database is CAplus.

A novel iodine promoted [1 + 3 + 2] cleavage cyclization reaction for the synthesis of 1H-pyrazolo[3,4-b]pyridines from aryl Me ketones, 5-aminopyrazoles and enaminones was established. This transition metal-free catalysis method has simple reaction conditions and good substrate compatibility, and was demonstrated in the transformation of alkyl and natural mol.-derived enaminones. Mechanistic studies showed that two cyclization pathways affording different key intermediates were involved, but affording the same target product after site-selective cleavage of the unstrained C-C bond of the acyl group.

Organic Chemistry Frontiers published new progress about 924-99-2. 924-99-2 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Amine,Aliphatic hydrocarbon chain,Ester, name is Ethyl 3-(dimethylamino)acrylate, and the molecular formula is C16H24BNO2, COA of Formula: C7H13NO2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Liu, Ping published the artcileEffects of Different Fermentation Strains on the Flavor Characteristics of Fermented Soybean Curd, COA of Formula: C6H12O3, the main research area is Actinomucor Rhizopus Mucor fermented soybean curd flavor; E-nose; HS-SPME-GC-MS; fermentation strains; fermented soybean curd; sensory evaluation.

The effects of different fermentation strains on the flavor characteristics of fermented soybean curd (FSC) were investigated in this study. Fresh tofu was fermented by Actinomucor elegans, Rhizopus arrhizus, Mucor racemosus, and Rhizopus chinensis, either alone or in various combinations. The FSC manufacturing process included prefermentation by different strains at 28 °C for 60 h, followed by salting at 16 °C for 7 days and finally proceeding postfermentation at 25 °C for 35 days. Subsequently, five tested samples were obtained, namely, sample A (fermented by A. elegans alone), R (fermented by R. arrhizus alone), AR (fermented by A. elegans and R. arrhizus at 5:1), AM (fermented by A. elegans and M. racemosus at 1:1), and RR (fermented by R. arrhizus and R. chinensis at 7:3). The flavors of the five samples were determined by E-nose, sensory evaluation, and GC-MS. E-nose system observed significant discriminations by principal component anal. and linear discriminant anal. anal. Sensory evaluation ranked the overall sensory scores: AR>AM>A>RR>R. As shown in GC-MS results, sample AR also had, on average, the highest level of many volatiles. Out of 10 critical volatiles, the detected frequency of samples AR, AM, RR, A, and R was 10, 9, 9, 8, and 7, resp. PLS2 regression model was used to explore the influence on flavor quality of different strains. All three analytic methods revealed similar results, with sample AR providing the best flavor quality, while the opposite was the case with sample R. Therefore, it could be concluded that A. elegans and R. arrhizus at 5:1 (volume/volume) was the optimal combination, and may likely promote the production of critical volatile compounds Practical Application : The flavors of fermented soybean curds are influenced by various factors such as physicochem. and microorganism during the fermentation surroundings. The results of this work not only provide valuable information for FSC flavor studies, but can also guide the FSC industry to improve flavor quality by applying the most appropriate production strains.

Journal of Food Science published new progress about Actinomucor elegans. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, COA of Formula: C6H12O3.

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

Yuan, Chuan published the artcileOptimization of hydrothermal co-liquefaction of seaweeds with lignocellulosic biomass: Merging 2nd and 3rd generation feedstocks for enhanced bio-oil production, Formula: C7H12O3, the main research area is lignocellulose rice husk Enteromorpha biooil hydrothermal coliquefaction process optimization.

The present work aimed to explore the optimized conditions of hydrothermal co-liquefaction (co-HTL) of the green seaweed “”Enteromorpha clathrata (EN)”” and the lignocellulosic agricultural waste “”rice husk (RH)””. Sep. hydrothermal liquefaction (HTL) of EN and RH showed bio-oil yields of 26.0% and 45.6%, resp. However, co-HTL under optimized conditions showed significant increase in the bio-oil yield by 71.7% over that of EN, and insignificant difference with that of RH. Nevertheless, the conversion ratio of co-HTL showed 10.6% significant increase over that of RH. GC-MS results showed that main compounds of EN and RH bio-oil lump into the C15-C20 and C5-C12 regions, mainly representing carbon range of diesel and gasoline, resp. Short-chain (C5-C12) and long-chain (C14-C20) compounds in the bio-oil obtained by co-HTL represented 72% and 28%, resp. In addition, the ratio of aromatic compounds in the bio-oil of RH was reduced by 9.3% as a result of co-HTL. In conclusion, results suggested 50% ethanol as a co-solvent, 300°C and 45 min as optimum conditions for co-HTL of EN:RH (1:1 weight/weight). The present study demonstrated an efficient route for co-HTL of 3rd generation feedstocks with 2nd generation feedstocks which will have a significant impact on large-scale applications.

Energy (Oxford, United Kingdom) published new progress about Agricultural wastes. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Formula: C7H12O3.

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

Yu, Haiyan published the artcileComprehensive two-dimensional gas chromatography mass spectrometry-based untargeted metabolomics to clarify the dynamic variations in the volatile composition of Huangjiu of different ages, Related Products of esters-buliding-blocks, the main research area is metabolome gas chromatog mass spectrometry dynamic variation volatile; Huangjiu aging; aroma attributes; comprehensive two-dimensional gas chromatography mass spectrometry; untargeted metabolomics; volatile compounds.

Aging plays an important role in the formation of aroma characteristics of Huangjiu, a traditional Chinese alc. beverage. Comprehensive two-dimensional gas chromatog. mass spectrometry (GCxGC-qMS)-based untargeted metabolomics combined with a multivariate anal. was used to investigate the dynamic variations in the aroma profile of Huangjiu during aging process and to establish the relationship between the changing volatile metabolite profiles and the age-dependent sensory attributes. A total of 144 volatile metabolites were identified by GCxGC-qMS and 63 were selected as critical metabolites based on variable importance in projection values and p-values. Based on the results of principal component anal., orthogonal partial least-squares discriminant anal., and hierarchical clustering anal., the samples of six different ages were divided into three groups: 1Y and 3Y samples, 5Y and 8Y samples, and 10Y and 15Y samples. The partial least-squares anal. results further revealed the relationship between the aromas attributes and variations of these volatile compounds The high esters, aldehydes, and lactones contents contributed to the high intensities of the sweet and ester aroma attributes of the aged Huangjiu, while the high alcs. and Et esters contents contributed to the alc. and fruity aroma attributes of the newly brewed Huangjiu. These results improve our understanding of the chem. nature of the aroma characteristics of aged Huangjiu. Huangjiu is often labeled with its age as a measure of quality, which influences consumers’ choice. Dynamic variations in volatile compounds of Huangjiu during aging and its contribution to the aroma characteristics of Huangjiu were figured out, which will assist the industry to produce better quality aged Huangjiu for consumers.

Journal of Food Science published new progress about Alcoholic beverages. 623-50-7 belongs to class esters-buliding-blocks, name is Ethyl 2-hydroxyacetate, and the molecular formula is C4H8O3, Related Products of esters-buliding-blocks.

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

Ichikawa, Eri published the artcileAnalysis of metabolites in Japanese alcoholic beverage sake made from the sake rice Koshitanrei, Product Details of C6H12O3, the main research area is Oryza alanine methionine sake alc beverage Japan; Koshitanrei; metabolite; metabolome analysis; rice; sake.

In sake brewing, the steamed rice is used in two ways, added to sake-mash (as kake-mai) and making koji. The rice is an important determinant for the quality of sake, as the metabolites in sake affect its taste/aroma. The sake rice Koshitanrei (KOS) was developed in Niigata Prefecture by genetically crossing two sake rice, Gohyakumangoku and Yamadanishiki. However, the metabolites in sake from KOS have not been analyzed. Here, to investigate the characteristic metabolites in sake from KOS, we performed two types of small-scale sake-fermentation tests changing only the rice used for kake-mai or total rice (both kake-mai and koji) by these three rice cultivars and examined the effect of KOS on sake metabolites by the metabolome anal. method using UPLC-QTOF-MS. We identified the peaks/metabolites, whose intensity in sake from KOS was higher/lower than those from the other cultivars. The brewing properties of KOS were partially characterized by this anal.

Bioscience, Biotechnology, and Biochemistry published new progress about Alcoholic beverages. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Product Details of C6H12O3.

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

Chen, Panpan published the artcileSensory-directed decoding of key aroma compounds from Jiugui-series Baijiu, the representative of Fuyu-flavor-type Baijiu (FFTB), Safety of Ethyl 4-oxopentanoate, the main research area is aroma compound fuyu flavor baijiu.

The key odorants of Jiugui-series Baijiu (Y and R) were explored systematically for the first time by a sensory-directed flavor anal. approach. A total of 144 aroma-active compounds were identified by pH regulated liquid-liquid extraction (LLE) and headspace solid phase microextaction (HS-SPME) combined with gas chromatog.-olfactometry-mass spectrometry (GC-O-MS), and 92 of these were first reported. The aroma extract dilution anal. (AEDA) was used for screening the potential important aroma compounds The overall aroma profiles of Y and R were successfully simulated (similarity = 95.47%, and 90.21%, resp.) by mixing the odorants (OAV �1) with their natural concentrations in 52% ethanol/water solutions The omission tests revealed that Et acetate, Et lactate, Et butyrate, Et pentanoate, Et hexanoate, Et octanoate, Et dodecanoate, di-Me trisulfide, acetic acid, propionic acid, butanoic acid, isovaleric acid, hexanoic acid, octanoic acid, and p-cresol were identified as the key aroma compounds In particular, benzenemethanethiol played an important role in the typical aroma of Y and R, which had a burnt or baked-like odor and was a new finding.

Journal of Food Composition and Analysis published new progress about Alcoholic beverages. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Safety of Ethyl 4-oxopentanoate.

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

Shrikhande, Savyasachi published the artcileIntensification and analysis of ethyl levulinate production process having a reactive distillation through vapor recompression and bottom flash techniques, Category: esters-buliding-blocks, the main research area is ethyl levulinate production process reactive distillation through vapor recompression.

Et levulinate (EL) is an important biodiesel blending ingredient. Reactive distillation (RD) and distillation are energy intensive operations in the EL process studied in this work. Therefore, the intensification approach for energy reduction in these operations is important. In this study, we investigated the implementation of vapor recompression (VR), multistage vapor recompression (MVR) and bottom flash (BF) techniques in the EL production process having one reactive distillation and two normal distillations for the first time. New intensified cases are- VR in RD (RD-VR), BF in RD (RD-BF), MVR in C1 column (C1-MVR), BF in C2 column (C2-BF), and hybrid RD-BF/C2-BF. Performance of these intensified cases is investigated and compared against the base case in terms of energy savings, total annual cost (TAC), carbon emission, energy consumed per ton of EL and cost of processing per kg of EL. It is found that the RD-BF/C2-BF scheme yields 61% reduction in overall heating duty, 35.5% reduction in TAC, and 58.76% reduction in carbon emission, with respect to the base case. Cost of EL production is found to be $ 6.6 per kg. This study is important as it focuses on economic as well as environmental aspects.

Chemical Engineering and Processing published new progress about Equilibrium constant. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Category: esters-buliding-blocks.

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