Month: January 2023

Efficient and reproducible synthesis of an Fmoc-protected Tn antigen was written by Piazza, Sabrina M.;Reynolds, Michael R.;Chiaramonte, Jonathan;Xu, Peihan;Chapa-Villarreal, Fabiola A.;Trant, John F.. And the article was included in New Journal of Chemistry in 2021.Electric Literature of C16H22O11 This article mentions the following:

This concise total synthesis of the Thomsen-Nouveau (Tn) glycoconjugate was accomplished using a palladium-catalyzed coupling between the glycosyl donor and Fmoc-protected serine acceptor. This is, to the best of our knowledge, the shortest synthesis reported from galactose for preparing this essential building block for large-scale solid phase peptide synthesis. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Electric Literature of C16H22O11).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Electric Literature of C16H22O11

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

Silicon-initiated carbonylative carbotricyclization and [2+2+2+1] cycloaddition of enediynes catalyzed by rhodium complexes was written by Bennacer, Bibia;Fujiwara, Masaki;Lee, Seung-Yub;Ojima, Iwao. And the article was included in Journal of the American Chemical Society in 2005.Category: esters-buliding-blocks This article mentions the following:

The reaction of dodec-11-ene-1,6-diynes or their heteroatom congeners with a hydrosilane catalyzed by Rh(acac)(CO)₂ at ambient temperature and pressure of CO gives the corresponding fused 5-7-5 tricyclic products, 5-oxo-1,3a,4,5,7,9-hexahydro-3H-cyclopenta[e]azulenes or their heteroatom congeners, in excellent yields through a unique silicon-initiated cascade carbonylative carbotricyclization (CO-SiCaT) process. It has also been found that the 5-7-5 fused tricyclic products can be obtained from the same type of enediynes and CO through a novel intramol. [2+2+2+1] cycloaddition process. The characteristics of these two tricyclization processes and the fundamental differences in their reaction mechanisms are discussed. This novel higher-order cycloaddition reaction has also been successfully applied to the tricyclization of undeca-5,10-diyn-1-als, affording the corresponding 5-7-5 fused-ring products bearing a seven-membered lactone moiety. Related [2+2+2] tricyclizations of enediyne and diynal substrates are also discussed. These newly discovered reactions can construct multiple bonds all at once, converting linear starting materials to polycyclic compounds in a single step. Thus, these new processes provide innovative routes to functionalized polycyclic compounds that are useful for the syntheses of natural and unnatural products. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Category: esters-buliding-blocks).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Category: esters-buliding-blocks

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

Catalytic esterification with solid acid HPM was written by Fu, Xiangkai;Liu, Qiang;Hua, Yanqing;Liu, Chenglun;Liu, Shoujun. And the article was included in Shiyou Huagong in 1989.Product Details of 1190-39-2 This article mentions the following:

Solid acid HPM (sic) was used as the catalyst for preparing 22 esters of acetic acid, propionic acid, propanedioic acid, and benzoic acid with yields of 76-96%. Exptl. results indicate esters from primary and secondary alcs. and aliphatic carboxylic acids, aliphatic dicarboxylic acids, and aromatic carboxylic acids can be obtained by direct esterification with the solid acid HPM catalyst. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Product Details of 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Product Details of 1190-39-2

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

Biodiesel production from biomass gasification tar via thermal/catalytic cracking was written by Laksmono, Nino;Paraschiv, Maria;Loubar, Khaled;Tazerout, Mohand. And the article was included in Fuel Processing Technology in 2013.COA of Formula: C12H22O4 This article mentions the following:

This paper is devoted to the study of valorization of tar from biomass gasification as a fuel for internal combustion engine. The methods selected were both thermal cracking and catalytic cracking in the presence of zeolite, magnesium oxide, and aluminum oxide catalyst. The chem. composition of the cracking product was analyzed by gas chromatog.-mass spectrometry, together with the physico-chem. properties determination (d., viscosity, higher heating value, and acidic value). Thermal cracking of biomass gasification tar gave a yield of biodiesel 73.67 weight% of feed. The cracking process in the presence of zeolite, magnesium oxide, and aluminum oxide catalysts gave a yield of biodiesel 62-75 weight%, 55-66 weight%, 67-71 weight% resp. The influence of the type and quantity of catalyst on production yield and properties of the produced bio-oil is highlighted. The produced bio-oil d. and heating value were close to the conventional diesel fuel. The viscosity and acidic value were found to be slightly higher than that of conventional diesel fuel. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6COA of Formula: C12H22O4).

Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.COA of Formula: C12H22O4

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

Transesterifications over titanosilicate molecular sieves was written by Srinivas, D.;Srivastava, R.;Ratnasamy, P.. And the article was included in Catalysis Today in 2004.Quality Control of malonic acid dibutyl ester This article mentions the following:

Titanosilicate mol. sieves (TS-1, Ti-MCM-41 and amorphous TiO₂-SiO₂) catalyze transesterification reactions. Acidity measurements (pyridine adsorption-IR and NH₃-TPD) reveal the presence of only weak Lewis acid sites. Catalytic activity parallels the acid strength and increases in the order: TS-1<Ti-MCM-41<amorphous TiO₂-SiO₂. TS-1 efficiently catalyzes the transesterification of only linear esters (Et acetoacetate and di-Et malonate), but fails for cyclic esters like propylene carbonate. Ti-MCM-41 and amorphous TiO₂-SiO₂ are superior for the latter. The catalysts could be recycled without any loss in activity/selectivity. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Quality Control of malonic acid dibutyl ester).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Quality Control of malonic acid dibutyl ester

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

Enantioselectivity of Pseudomonas cepacia lipase for the acetylation of 2-hydroxy carboxylic acid esters was written by Sundholm, Oskari;Kanerva, Liisa T.. And the article was included in ACH – Models in Chemistry in 1998.Formula: C11H14O3 This article mentions the following:

Structurally different Et or Me 2-hydroxy carboxylates were resolved by Pseudomonas cepacia lipase-catalyzed acetylations with vinyl acetate in di-Et ether. One type of the alc. substrates (2-hydroxy-2-arylacetates and 2-hydroxy-3-arylpropionates) contained a hydroxy group at the stereocenter. These compounds were resolved with high enantioselectivity (ee 91-99%) at ca. 50% conversion. The other alc. substrates [threo-2-hydroxy-3-methylbutyrate and threo- or erythro-2-hydroxy-3-aryl-3-arylthio(or aryloxy)propionates] with two stereocenters generally resulted in enantiopure products, and the reactions stopped at 50% conversion. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0Formula: C11H14O3).

Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Formula: C11H14O3

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

The influence of polyphenol supplementation on ester formation during red wine alcoholic fermentation was written by Ling, Mengqi;Qi, Mengyao;Li, Siyu;Shi, Ying;Pan, Qiuhong;Cheng, Chifang;Yang, Weiming;Duan, Changqing. And the article was included in Food Chemistry in 2022.Safety of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate This article mentions the following:

Pre-fermentative polyphenol supplementation in industrial scales (100-hL) and simulated fermentation (350 mL clarified juice) were conducted. The results showed that in practical winemaking, adding QCE (quercetin, caffeic acid and ellagic acid) increased acetate concentrations in wines and extra grape seed tannins (T) enhanced the effect of QCE supplementation. In simulated fermentation with clarified juice, the synergy effect of QCE and T was evidenced that ester formation was only promoted through mixed QCET supplementation. Besides, QCE supplementation benefited the formation of 4-vinylcatechol adducted malvidin-3-O-(acetyl/coumaroyl)-glucoside and decreased other anthocyanin derivatives derived from pyruvic acid and acetaldehyde, leading more pyruvic acid and acetaldehyde left in yeast to enhance the metabolic fluxes of esters. Findings manifested the connection between the formation of esters and anthocyanin derivatives during red wine alc. fermentation, which would be influenced by the phenolic matrix. This work could provide a perspective in winemaking industry for modulating aroma profile via polyphenol supplementation. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Safety of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Safety of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate

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

An approach to pseudomonic acids from acetylenic precursors: synthesis of 2-(hydroxymethyl)-3-butyn-1-ol was written by Bates, Hans Aaron;Farina, James;Tong, Michael. And the article was included in Journal of Organic Chemistry in 1986.Computed Properties of C9H16O4 This article mentions the following:

The acetonide of 2-(hydroxymethyl)-3-butyn-1-ol (I) was prepared from (HOCH₂)₂C(CO₂Et)₂ or from (HOCH₂)₂CO. Alternative routes to I involving the highly unstable HOCH₂C(CHO)CCH or its acetate were unsuccessful. Condensation of the anion of I with 3-oxobutanal ethylene acetal followed by semihydrogenation and deprotection afforded MeCOCH₂CH(OH)CH:CHCH(CH₂OH)₂, which cyclized stereoselectivity to the dihydropyran II. Osmylation of II and functional group manipulation afforded the diol III, a precursor to pseudomonic acid C. In the experiment, the researchers used many compounds, for example, Ethyl 2,2-dimethyl-1,3-dioxane-5-carboxylate (cas: 82962-54-7Computed Properties of C9H16O4).

Ethyl 2,2-dimethyl-1,3-dioxane-5-carboxylate (cas: 82962-54-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Computed Properties of C9H16O4

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

Photochemistry of enolizable β-dicarbonyl compounds: study on the photoketonization of some esters of aroylacetic acids was written by Markov, P.;Petkov, I.;Eglova, D.. And the article was included in Journal of Photochemistry in 1978.HPLC of Formula: 33166-79-9 This article mentions the following:

Photolysis of RC₆H₄COCH₂CO₂Et (R = H, Me, MeO, NO₂, Cl, Br) results in a shift of the keto-enol equilibrium toward the keto form. Rate constants and quantum yields were determined Electron-releasing substituents in the para position favor ketonization. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9HPLC of Formula: 33166-79-9).

Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.HPLC of Formula: 33166-79-9

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

Synthesis of disaccharide modified berberine derivatives and their anti-diabetic investigation in zebrafish using a fluorescence-based technology was written by Wang, Lizhen;Kong, Haotian;Jin, Meng;Li, Xiaobin;Stoika, Rostyslav;Lin, Houwen;Liu, Kechun. And the article was included in Organic & Biomolecular Chemistry in 2020.HPLC of Formula: 4163-60-4 This article mentions the following:

Berberine is a naturally occurring isoquinoline alkaloid and has been used as an important functional food additive in China due to its various pharmacol. activities. Berberine exhibits great potential for developing anti-diabetic agents against type 2 diabetes mellitus (T2DM), as it can reduce the blood glucose level in many animal models. However, the low anti-diabetic activity and poor bioavailability of berberine (below 5%) by oral administration significantly limit its practical applications. To solve these problems, this article focuses on the structural modification of berberine using some disaccharide groups, because the carbohydrate moiety has been proved to improve the bioavailability and enhance the receptor-binding affinity of drugs. Anti-diabetic investigation of the synthesized compounds was performed in a zebrafish model using a fluorescently labeled glucose analog 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) as a glucose tracker. The results indicated that the modification of berberine with carbohydrate groups could give derivatives with improved anti-diabetic activity, in particular the diglucose modified berberine derivative I which could dramatically promote the uptake of 2-NBDG in both zebrafish larvae and their eyes even at very low concentrations Furthermore, the fluorescence-based anti-diabetic investigation method in zebrafish shows great potential for anti-diabetic drug screening. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4HPLC of Formula: 4163-60-4).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.HPLC of Formula: 4163-60-4

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