Tag: 116.1583

The conformational behavior of 2-aryloxytetrahydropyrans and 2-acetoxytetrahydropyran, and barrier to ring inversion was written by Ouedraogo, Adama;Lessard, Jean. And the article was included in Canadian Journal of Chemistry in 1991.Electric Literature of C6H12O2 This article mentions the following:

The ¹³C NMR data of a series of 2-(4-substituted phenoxy)tetrahydropyrans at 156 K and in CF₂Br₂ and CHFCl₂ solvents show that the axial preference increases with electron withdrawal in the aryloxy group: from 79% (ΔG°_E→A = -0.4 kcal mol^-1) (4-OCH₃) to 90% (ΔG°_E→A = -0.7 kcal mol^-1) (4-NO₂) in CF₂Br₂. The axial preference (anomeric effect) is smaller in the more polar CHFCl₂ solvent, as expected, and the substituent effect is smaller also: change in ΔG°_E→A from -0.3 (4-OCH₃) to -0.5 (4-NO₂) kcal mol^-1. However, the axial preference of 2-acetoxytetrahydropyran is shown to be smaller than that of 2-phenoxytetrahydropyran in CF₂Br₂ solvent although the acetoxy group is expected to be more electroneg. than the phenoxy group. Furthermore, the polarity of the solvent has no effect on the conformational equilibrium of 2-acetoxytetrahydropyran. The results are interpreted in terms of both orbital and electrostatic interactions. The ring-inversion barrier of 2-alkoxy- and 2-aryloxytetrahydropyrans, determined by the temperature-coalescence method, is lower than that of tetrahydropyran by about 1.5 kcal mol^-1. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Electric Literature of C6H12O2).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. In organic synthesis, the 2-tetrahydropyranyl group is used as a protecting group for alcohols. The Prins reaction of homoallylic alcohols with aldehydes afforded an alternative method for the preparation of tetrahydropyrans.Electric Literature of C6H12O2

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

Sensing or No Sensing: Can the Anomeric Effect Be Probed by a Sensing Molecule? was written by Wang, Chang-Wei;Ying, Fu-Ming;Wu, Wei;Mo, Yi-Rong. And the article was included in Journal of the American Chemical Society in 2011.Recommanded Product: 6581-66-4 This article mentions the following:

The anomeric effect plays a central role in carbohydrate chem., but its origin is controversial, and both the hyperconjugation model and the electrostatic model have been proposed to explain this phenomenon. Recently, Cocinero et al. designed a peptide sensor, which can bind to a sugar mol. Me D-galactose, and claimed that the anomeric effect can be sensed by the spectral changes from the β- to the α-complex, which are ultimately attributed to the lone pair electron d. change on the endocyclic oxygen atom. Here, we provide strong computational evidence showing that the observed spectral changes simply come from the conformational differences between the α- and β-anomers, as the replacement of the endocyclic oxygen atom with a methylene group, which disables both the endo- and the exo-anomeric effects in Me D-galactose, leads to similar spectral shifts. In other words, the “sensor” cannot probe the anomeric effect as claimed. We further conducted detailed energetic and structural analyses to support our arguments. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Recommanded Product: 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyran is a useful synthetic intermediate. Tetrahydropyranyl (THP-) ethers derived from the reaction of alcohols and dihydropyran are common intermediates in organic synthesis. Pyran derivatives such as pyran flavonoids are biologically important. Monosaccharides containing six-membered rings are called pyranose.Recommanded Product: 6581-66-4

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

Ferrous methanesulfonate as an efficient and recyclable catalyst for the tetrahydropyranylation of alcohols and phenols under solvent-free conditions was written by Wang, Min;Song, Zhiguo;Wan, Xin;Zhao, Shuang. And the article was included in RSC Advances in 2011.Application of 6581-66-4 This article mentions the following:

The synthesis of the target compounds was achieved by a ferrous methanesulfonate-catalyzed tetrahydropyranylation of alcs. (benzylic, primary, isomeric alcs., tertiary, cyclic, allyl and furyl) and phenols at room temperature under solvent-free conditions (green chem. method). The catalytic activity of sixteen metal methanesulfonates was compared under the same conditions, ferrous methanesulfonate proved to be the best. It can be recovered easily and reused for several times without distinct deterioration in catalytic activity. During a competitive protection of the hydroxyl groups between an alc. and a phenol, tetrahydropyranyl ether formed exclusively with the alc. A possible catalytic mechanism was proposed. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Application of 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyran is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and dyestuff. One classic procedure for the organic synthesis of tetrahydropyran is by hydrogenation of the 3,4-isomer of dihydropyran with Raney nickel.Application of 6581-66-4

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

Unrecognized Intramolecular and Intermolecular Attractive Interactions between Fluorine-Containing Motifs and Ether, Carbonyl, and Amino Moieties was written by Wiberg, Kenneth B.;Bailey, William F.;Lambert, Kyle M.. And the article was included in Journal of Organic Chemistry in 2019.Related Products of 6581-66-4 This article mentions the following:

In order to elucidate to what extent Coulombic and other interactions contribute to the origins of contrasteric phenomena, we have identified a significant, previously unrecognized interaction between fluorine-containing motifs and groups or mols. containing main-group heteroatoms. The axial conformers of both 2-methoxy- and 2-trifluoromethoxytetrahydropyrans preferentially adopt a rotameric arrangement in which the OCH₃ and the OCF₃ groups are gauche to the ring oxygen. Given that one would expect a repulsive Columbic interaction to exist between the electroneg. fluorines of the CF₃ group and the ring oxygen in this rotameric orientation, this surprising result suggests that an attractive interaction exists between the CF₃ group and the oxygen of the ring. The generality and origin of this interaction was examined using nonpolar CF₄ to probe intermol. interactions with systems such as di-Me ether, trimethylamine, trimethylphosphine, and acetone. In each case there was an attractive interaction leading to formation of a complex. The attraction is not due to van der Waals forces. Rather, the fluorine lone pairs of the CF₄ often act as an electron donor in these complexes leading to a transfer of charge between the reactants and formation of the complex. These previously unrecognized fluorine-heteroatom interactions likely play a significant role in the context of understanding the binding interactions of medicinally relevant mols. or pharmaceuticals possessing fluorine-containing pharmacophores with their targets. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Related Products of 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Dihydropyrans and tetrahydropyrans are examples of cyclic ethers widespread in nature. The Prins reaction of homoallylic alcohols with aldehydes afforded an alternative method for the preparation of tetrahydropyrans.Related Products of 6581-66-4

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

Synthesis of gem-Difluoroalkenes via Nickel-Catalyzed Reductive C-F and C-O Bond Cleavage was written by Lin, Zhiyang;Lan, Yun;Wang, Chuan. And the article was included in ACS Catalysis in 2019.Recommanded Product: 2-Methoxytetrahydro-2H-pyran This article mentions the following:

By merging C-O and C-F bond cleavage in cross-electrophile coupling, we developed a method for efficient synthesis of gem-difluoroalkenes with an alkoxy-substituent on the homoallylic position using easily accessible acetals as coupling partners with α-trifluoromethyl alkenes. Remarkably, this Ni-catalyzed allylic defluorinative cross-coupling reaction demonstrates high tolerance of a wide range of sensitive functional groups and proves to be applicable in late-stage functionalization of structurally complex compounds In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Recommanded Product: 2-Methoxytetrahydro-2H-pyran).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyrans and furans principally constitute as a central motif in diverse medicinally privileged molecules. The most notable anticancer agent, bryostatin, and eribulin are marine macrolides having intriguing tetrahydropyran and furan motif. Recommanded Product: 2-Methoxytetrahydro-2H-pyran

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

Ab initio molecular orbital calculation of carbohydrate model compounds. 2. Conformational analysis of axial and equatorial 2-methoxytetrahydropyrans was written by Tvaroska, Igor;Carver, Jeremy P.. And the article was included in Journal of Physical Chemistry in 1994.Application of 6581-66-4 This article mentions the following:

An ab initio study of the conformational behavior of α- and β-glycosidic linkages has been carried out on axial and equatorial 2-methoxytetrahydropyrans as models. The geometry of the conformers about the glycosidic C-O bond was determined by gradient optimization at the SCF level using the 4-21G and 6-31G* basis sets and at the second-order Moeller-Plesset level using the MP2/6-31G* basis set. The potential of rotation has been calculated using 4-21G, 6-31G*, 6-31+G*, MP2/6-31G*, and 6-311++G** basis sets. At all levels of theory, both axial and equatorial forms prefer the GT conformation around the C-O glycosidic bond. Conformational changes in bond lengths and angles at the anomeric center also display significant variations with computational methods, but structural trends are in fair agreement with experiment The corrections for the effect of zero-point energy, thermal energy, and entropy on the axial-equatorial energy difference at the 6-31G* level is -0.63 kcal/mol. After these corrections to the energy difference calculated at the 6-31G* level, the axial form is favored by 0.84 kcal/mol, in reasonable agreement with exptl. values of ΔG = 0.7-0.9 kcal/mol estimated for nonpolar solvents. Solvent effects reduce this energy difference; in the extreme case of water, a value of 0.24 kcal/mol was obtained. Complete torsional profiles have been obtained for rotation about the glycosidic C-O bond in eleven solvents, and the calculated energy differences are in fair agreement with exptl. data on 2-alkoxytetrahydropyrans in solutions The MM3 (ε = 1.5) force field reproduces the 6-31G* ab initio energy difference reasonably well, but barrier heights are in poor agreement with the ab initio data. The calculated energies and geometries provide an essential set of data for the parametrization of the behavior of acetal fragments in mol. mech. force fields for carbohydrates. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Application of 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyrans are useful synthons for biologically important compounds. There is large number of marine macrolide natural products that contain tetrahydropyran and tetrahydrofuran ring together. For instance, goniodomin A (actin targeting polyether), prorocentrolide (toxin halistatins), and percentotoxineApplication of 6581-66-4

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

Conformational analysis and study of anomeric effect on 2-alkoxytetrahydropyrans by molecular mechanics (MM2) and theoretical 3JHH calculation was written by Florido Navio, Pilar;Molina Molina, Jose. And the article was included in Journal of Molecular Structure in 1990.COA of Formula: C6H12O2 This article mentions the following:

Mol. mechanics calculations were carried out for conformers of 2-alkoxytetrahydropyran derivatives with the alkoxy group in the axial and equatorial conformations. According to the numerical results obtained, the anomeric effects can be predicted as well as the geometry tendencies of the different conformers studied. Thus, the coupling constants 2-3 are calculated theor., giving results consistent with the exptl. data. Comparisons are made using different effective dielec. constants, and carrying out calculations with different versions of MM2. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4COA of Formula: C6H12O2).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyrans are also used as important solvents, as chemical intermediate and as monomer for ring-opening polymerization. 2-(Arylmethylene)cyclopropylcarbinols could be converted to the corresponding tetrahydropyrans stereoselectively in the presence of Brønsted acids under mild conditions. A plausible Prins-type reaction mechanism has been proposed.COA of Formula: C6H12O2

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

Ab Initio Examination of Anomeric Effects in Tetrahydropyrans, 1,3-Dioxanes, and Glucose was written by Salzner, Ulrike;Schleyer, Paul v. R.. And the article was included in Journal of Organic Chemistry in 1994.Application In Synthesis of 2-Methoxytetrahydro-2H-pyran This article mentions the following:

Axial and equatorial structures of 2-methyl-, 2-hydroxy-, 2-methoxy-, 2-amino-, 2-fluoro-, and 2-chlorotetrahydropyran, of the 2-tetrahydropyranylammonium cation, of 2-methyl-, 2-hydroxy, and 2-methoxy-1,3-dioxane, and of the corresponding cyclohexanes have been fully optimized at the HF/6-31G^* level. NBO anal. of the Hartree-Fock wave functions confirms that the anomeric effects of hydroxy-, methoxy-, fluoro-, and chloropyrans and of glucose and Me glucoside are indeed due to hyperconjugation. In cyclohexane, tetrahydropyran, and glucose theor. ΔE values involving the OH and OMe substituents are nearly identical. The exptl. observed differences of about 1 kcal/mol in the ΔH° and ΔG° values of the OH and OMe compounds are very likely due to solvent interactions involving the OH group. In the gas phase glucose orients its ring hydroxy groups and the CH₂OH group differently than in the crystal. The structures observed in the crystal lead to 7.9 kcal/mol higher energies. This might be rationalized by the fact that the isolated mol. tries to maximize the number of intramol. hydrogen bonds. 2-Hydroxy-1,3-dioxane prefers an equatorial conformation. NBO anal. reveals that the exo-anomeric effect favoring the equatorial form dominates over the endo-anomeric effect in dioxanes. In contrast, 2-methoxy-1,3-dioxane shows an axial preference which is not due to hyperconjugation. The reverse anomeric effect in 2-aminotetrahydropyran is due to steric repulsions because the axial conformation with the largest hyperconjugation contribution requires one of the NH₂ hydrogens to point above the ring. The equatorial preference of NH₃⁺ is a result of steric and other (probably electrostatic) contributions, since hyperconjugation strongly favors the axial conformation. For all cases for which the hyperconjugation contributions are overcompensated by the Lewis energies, steric repulsions are also indicated by significant ring distortions. Dipole moments correlate with relative energies qual. in some cases, but a quant. relationship cannot be ascertained. Single point calculations with Huzinaga basis sets reveal that at the HF/6-31G^* level axial-equatorial energy differences of all compounds considered in this investigation are biased toward axial structures by 0.5-1 kcal/mol. Thus, the 6-31G^* basis set fails to reproduce the small equatorial preference of 2-fluorohexane at the HF as well as at correlated levels. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4Application In Synthesis of 2-Methoxytetrahydro-2H-pyran).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Dihydropyrans and tetrahydropyrans are examples of cyclic ethers widespread in nature. The reaction of tertiary 1,4- and 1,5-diols with cerium ammonium nitrate at room temperature gives tetrahydrofuran and tetrahydropyran derivatives in high yield and stereoselectivity. Various fragrant compounds have been synthesized using this method.Application In Synthesis of 2-Methoxytetrahydro-2H-pyran

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

Stereoselective gem-C,B-Glycosylation via 1,2-Boronate Migration was written by Zhao, Wei-Cheng;Li, Rui-Peng;Ma, Chao;Liao, Qi-Ying;Wang, Miao;He, Zhi-Tao. And the article was included in Journal of the American Chemical Society in 2022.HPLC of Formula: 6581-66-4 This article mentions the following:

A novel protocol is established for the long-standing challenge of stereoselective geminal bis-glycosylations of saccharides. The merger of PPh₃ as a traceless glycosidic leaving group and 1,2-boronate migration enables the simultaneous introduction of C-C and C-B bonds at the anomeric stereogenic center of furanoses and pyranoses. The power of this method is showcased by a set of site-selective modifications of glycosylation products for the construction of bioactive conjugates and skeletons. A scarce metal-free 1,1-di-functionalization process of alkenes is also concomitantly demonstrated. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4HPLC of Formula: 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyran is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and dyestuff. The most notable anticancer agent, bryostatin, and eribulin are marine macrolides having intriguing tetrahydropyran and furan motif. HPLC of Formula: 6581-66-4

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

Evaluation of susceptibility and resistance of human infectious bacteria and identification of bioactive compounds in Pistacia atlantica, Cassia absus, and Quercus persica was written by Alamholo, Mostafa;Amraie, Yosof. And the article was included in Pharmaceutical and Biomedical Research in 2021.SDS of cas: 6581-66-4 This article mentions the following:

Background: The antimicrobial activity of plants has long been considered an effective mechanism for controlling pathogenic microorganisms. Objectives: This study aimed to identify phytochem. compounds of the seed extracts from ethnomedicinal plants of Pistacia atlantica, Cassia absus, and Quercus persica with Gas Chromatog.-Mass Spectrometry (GC-MS) and investigation of their antibacterial and antioxidant activities. Methods: The seeds were collected from Lorestan Province, Iran. Their antibacterial and antiradical activities were analyzed by disk-diffusion and 2,2-diphenyl-1-picrylhydrazyl assays, resp. Ethanol (96%), methanol (80%), and distilled water extracts were obtained by the maceration method. The methanol extract was used for the anal. of chem. compositions Results: About 40, 31, and 8 compounds were identified by GC-MS in the seeds of Cassia absus, Pistacia atlantica, and Quercus persica, resp. Results indicated that 2,4-di-tertbutylphenol (36.043%) and tetradecanoic acid (4.92%) were dominated in the seed extracts of Cassia absus. However, germacyclopetene (38.119%) and 1,2,3-benzenetriol (8.115%) were dominated in the seed extracts of Pistacia atlantica. Furthermore, 5H-tetrazole-5-thione, 1,4-dihydro-1,4-dimethy (38.505%), and tetradecanoic acid (30.546%) were dominated in the seed extracts of Quercus persica. The strongest radical scavenging activity and the highest inhibitory activity against M. luteus were observed on the methanol extract of C. absus. was changed to The highest inhibitory activity against M. luteus was observed on the methanol extract of C. absus. Conclusion: Because of the presence of antimicrobial compounds in the tested ethnomedicinal plants, they can be used to synthesize new antimicrobial drugs in medicinal and pharmaceutical sciences. In the experiment, the researchers used many compounds, for example, 2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4SDS of cas: 6581-66-4).

2-Methoxytetrahydro-2H-pyran (cas: 6581-66-4) belongs to tetrahydropyran derivatives. Tetrahydropyrans are useful synthons for biologically important compounds. 2-(Arylmethylene)cyclopropylcarbinols could be converted to the corresponding tetrahydropyrans stereoselectively in the presence of Brønsted acids under mild conditions. A plausible Prins-type reaction mechanism has been proposed.SDS of cas: 6581-66-4

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