Month: January 2023

Quinuclidine. Bicyclo[2.2.2]-aza-1-octane was written by Kohlbach, D.;Cerkovnikov, E.;Rezek, A.;Piantanida, M.. And the article was included in Justus Liebigs Annalen der Chemie in 1937.Recommanded Product: Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate This article mentions the following:

Tetrahydropyranyl-4-carbinol and PBr₃ in C₅H₅N give, after 2 days, 58.5% of 4-bromomethyltetrahydropyran, b₁₇ 85-6°; refluxing with KCN in EtOH yields 83% of tetrahydropyran-4-acetonitrile, b₂₁ 125-6°; alk. hydrolysis gives 63% of tetrahydropyran-4-acetic acid (I), b₂₀ 178°, m. 54-5°. Tetrahydropyran-4-ol (II) and PhSO₂Cl with 5 N NaOH give 58% of the phenylsulfonate (III), pale brown oil, which was not purified but was caused to react with CHNa(CO₂Et)₂ to give 81% of the di-Et ester (IV), b₁₃ 156-60°, of tetrahydropyran-4-malonic acid, m. 151°; on heating it yields I. II and PBr₃ in C₅H₅N yield 52% of 4-bromotetrahydropyran, b₁₅ 60-1°; the reaction with CHNa(CO₂Et)₂ gives a smaller yield of IV than does III. Tetrahydro-γ-pyrone (V), BrCH₂CO₂Et and Zn in C₆H₆ give 43% of Et 4-hydroxy-tetrahydropyran-4-acetate, b₁₅ 132-40°, Ac derivative, b₂₁ 140-5°; distillation of the Ac derivative at room temperature (the operation is repeated 3 times) gives 77% of Et tetrahydropyranylidene-4-acetate, b₁₅ 113°, d₄^13.1 1.0663, n 1.4766, 1.4798, 1.4886, 1.4961 for α, He, β and γ at 13.1°; catalytic reduction (PtO₂) gives 91% of Et tetrahydropyran-4-acetate (VI), b₁₄ 108-10°, d₄^13.4 1.0268, n 1.4448, 1.4469, 1.4526, 1.4572 for α, He, β and γ at 13.4°. I, NCCH₂CO₂Et and piperidine in C₆H₆, heated 12 hrs., give 84% of Et tetrahydropyranylidene-4-(α-cyanoacetate) (VII), b₁₅ 156-9°, m. 66-7°; the free acid m. 137-8° (hydrolysis with dilute HCl); saponification with EtOH-KOH does not give the desired dicarboxylic acid; distillation of the free acid yields 50% of Δ³-dihydropyranacetonitrile, b₂₃ 135°, transformed by refluxing with 20% EtOH-H₂SO₄ for 62 hrs. into 15% of Et Δ³-dihydropyranacetate, b. 112-20° (in vacuo), d₄^17.8 1.0610, n 1.4614, 1.4639, 1.4711 for α, He and β at 17.6°; catalytic reduction gives VI. VII and p-BrC₆H₄COCH₂Br with EtONa in EtOH give Et α-cyano-α-Δ³-dihydropyranyl-4-β-(p-bromobenzoyl) propionate, m. 153-4°. A by-product of VII is the compound C₁₈H₂₀O₅N₂, m. 260° (decomposition); it contains an EtO group and a H atom titratable with alkali and phenolphthalein. Reduction of VI (Na and EtOH in benzine) gives 40% of 4-(β-hydroxyethyl)tetrahydropyran, b₁₄ 119-20°; phenylurethan, m. 70-1°; fuming HBr (6 hrs. at 100-10°) yields 80% of 3-(2-bromoethyl)-1,5-dibromopentane, b₁₇ 185-6°; heating with 20% MeOH-NH₃ at 130-40° gives 50% of quinuclidine, m. 158-9°; picrate, yellow, m. 275-6°. I and fuming HBr give β-(β’-bromoethyl)-δ-bromovaleric acid, which was esterified and heated with 20% MeOH-NH₃, yielding 20% of the Et ester, b₁₅ 123-7° (chloroplatinate, m. 192° (decomposition)), of piperidine-4-acetic acid, m. 237-8° (decomposition); chloroplatinate, orange, m. 210-13° (decomposition); phenylsulfonate. In the experiment, the researchers used many compounds, for example, Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2Recommanded Product: Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate).

Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2) belongs to tetrahydropyran derivatives. Tetrahydropyran is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and dyestuff. The bismuth chloride-assisted cross-cyclization between homoallylic alcohols and epoxides provided various benzyl tetrahydropyran derivatives. The reaction afforded good yields of desired products and occurred under mild conditions.Recommanded Product: Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate

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

New high affinity H₃ receptor agonists without a basic side chain was written by Kitbunnadaj, Ruengwit;Hoffmann, Marcel;Fratantoni, Silvina A.;Bongers, Gerold;Bakker, Remko A.;Wieland, Kerstin;el Jilali, Ahmed;De Esch, Iwan J. P.;Menge, Wiro M. P. B.;Timmerman, Henk;Leurs, Rob. And the article was included in Bioorganic & Medicinal Chemistry in 2005.Synthetic Route of C9H16O3 This article mentions the following:

In this study, we replaced the basic amine function of the known histamine H₃ receptor agonists imbutamine or immepip with non-basic alc. or hydrocarbon moieties. All compounds in this study show a moderate to high affinity for the cloned human H₃ receptor and, unexpectedly, almost all of them act as potent agonists. Moreover, in the alc. series, we consistently observed an increased selectivity for the human H₃ receptor over the human H₄ receptor, but none of the compounds in this series possess increased affinity and functional activity compared to their alkylamine congeners. In this new series of compounds VUF5657, 5-(1H-imidazol-4-yl)-pentan-1-ol, is the most potent histamine H₃ receptor agonist (pK_i = 8.0 and pEC₅₀ = 8.1) with a 320-fold selectivity at the human H₃ receptor over the human H₄ receptor. In the experiment, the researchers used many compounds, for example, Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2Synthetic Route of C9H16O3).

Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2) belongs to tetrahydropyran derivatives. Tetrahydropyrans are also used as important solvents, as chemical intermediate and as monomer for ring-opening polymerization. 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 percentotoxineSynthetic Route of C9H16O3

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

Alkaline epoxidation of α,β-unsaturated aldehydes was written by Payne, George B.. And the article was included in Journal of Organic Chemistry in 1961.Category: tetrahydropyran This article mentions the following:

Using the previously described procedure, MeCH:CHCHO (I) was epoxidized to yield 77% flashed aqueous epoxy aldehyde, RCH.CR'(CHO).O (II, R = Me, R’ = H), which gave 56% anhydrous product. For epoxidation of relatively H₂O-insoluble unsaturated aldehydes, MeOH was used as solvent. MeOH (300 ml.) containing 0.55 mole 30% H₂O₂ stirred at 35-40°, with cooling in a 5-necked flask provided with stirrer, dropping funnels, and standard electrodes attached to a Beckman pH meter, with dropwise addition in 10 min. of 56 g. 3-formyl-5,6-dihydro-2H-pyran (III) and addition of N NaOH to maintain meter pH 9 (corresponding to indicator paper pH 8), the mixture stirred 1.5 hrs. (consumption of 0.52 mole peroxide and 19 ml. N NaOH) and concentrated in vacuo, the concentrate saturated with (NH₄)₂SO₄ and extracted 3 times with 150 ml. CHCl₃, the washed (saturated (NH₄)₂SO₄) and dried (MgSO₄) extract concentrated, and the residue distilled through a glass helices-packed column yielded 70% epoxy aldehyde. In a similar flask 1 l. MeOH and 0.10 mole 30% H₂O₂ stirred with cooling at 35-40° 1 hr. with alternate portionwise addition of 132 g. PhCH:CHCHO (IV) in 100 ml. MeOH, 1.0 mole 30% H₂O₂, and N aqueous NaOH at constant meter pH 10.5-11.0 (pH 8-8.5 by indicator paper), the mixture kept 1 hr. at meter pH 10.0-10.5 and 35°, concentrated to 300 ml. and diluted with 1 l. H₂O, extracted 3 times with 300 ml. Et₂O and concentrated at 20° to constant weight (136 g. containing 0.08 mole organic peroxide), the residue taken up in 50 ml. C₆H₆ and hydrogenated 30 min. at 20°/50 lb./sq. in. with 3 g. 5% Pd-C, the filtered solution distilled and the product (79 g., b_0.5 65-90°) redistilled through a 10-tray Oldershaw column yielded 24% β-phenylglycidaldehyde. Results obtained similarly with I, MeCH:CMeCHO, III, IV, and citral are summarized (R, R’ of II, or starting compound, % yield, b.p./mm., n²⁰_D, and m.p. of 2,4-dinitrophenylhydrazone given): Me, H, 56, 60-1°/80, 1.4179, 136-8°; Me, Me, 46, 58-9°/60, 1.4198, -; III, 70, 56-7°/2.0, 1.4739, 136-6.5°; Ph, H, 24, 70-2°/0.3, 1.5448, 138-9°; citral, 75, 63-7°/1.0, 1.4609, -. II from I, MeCH:CMeCHO, and citral are new compounds In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Category: tetrahydropyran).

5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) belongs to tetrahydropyran derivatives. Tetrahydropyrans and furans principally constitute as a central motif in diverse medicinally privileged molecules. 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.Category: tetrahydropyran

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

Tricarbocyanines with dihydropyran, dihydrothiapyran, and N-methyltetrahydropyridine rings in chromophore was written by Tolmachev, A. I.;Slominskii, Yu. L.;Belaya, Zh. N.;Rodova, E. Z.. And the article was included in Khimiya Geterotsiklicheskikh Soedinenii in 1976.Synthetic Route of C6H8O2 This article mentions the following:

Tricarbocyanines with γ,γ’-oxydimethylene, -thiodimethylene, or -(methylimino)dimethylene bridges [I; R = H or (RR) = benzo; R1 = H, Cl; X = Br, iodine, p-MeC6H4SO3; X1 = O, S, NMe] were prepared from benzothiazolium salts and the resp. diformyl heterocyclic compound dianils, and their spectra determined The hetero atom in the bridge causes a slight hypsochromic shift in the spectra of both I and the dianil intermediates, presumably due to a neg. inductive effect. Protonation of the imino group magnifies the effect. In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Synthetic Route of C6H8O2).

5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) belongs to tetrahydropyran derivatives. Tetrahydropyrans and furans principally constitute as a central motif in diverse medicinally privileged molecules. One classic procedure for the organic synthesis of tetrahydropyran is by hydrogenation of the 3,4-isomer of dihydropyran with Raney nickel.Synthetic Route of C6H8O2

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

The compressional properties of dextrose monohydrate and anhydrous dextrose of varying water contents was written by Armstrong, N. Anthony;Patel, Anil;Jones, Trevor M.. And the article was included in Drug Development and Industrial Pharmacy in 1986.Product Details of 14431-43-7 This article mentions the following:

The effect of moisture on the compressional properties of anhydrous dextrose  [50-99-7] and dextrose monohydrate (I) [14431-43-7] was examined Relations between moisture content and both tablet tensile strength and tablet toughness were evaluated. An increase in the moisture content of anhydrous dextrose produced a corresponding increase in both strength parameters up to the 8.9% moisture level, possibly due to a recrystallizing effect. However any further increase in moisture content beyond this point produced a marked reduction in both tablet tensile strength and tablet toughness. For I, any increase in moisture content obtained by exposure to elevated humidities led to a reduction in both tensile strength and toughness. The consolidation of both anhydrous dextrose and I was improved with increasing moisture content, presumably due to a lubrication effect. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7Product Details of 14431-43-7).

(2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7) belongs to tetrahydropyran derivatives. Tetrahydropyrans are useful synthons for biologically important compounds. 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.Product Details of 14431-43-7

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

Lyoluminescent dosimetry of ionizing radiation was written by Matyushkov, V. V.;Mikhal’chenko, G. A.;Sigaev, V. Ya.;Yudin, I. V.;Lymarev, A. V.. And the article was included in Izvestiya Akademii Nauk SSSR, Seriya Fizicheskaya in 1977.COA of Formula: C6H14O7 This article mentions the following:

The possibility is discussed of a method of dosimetry of ionizing radiation based on the dissolution of irradiated solid substances. The anticipated limiting sensitivity of the method is 10-3 rad. The carbohydrates studied were glucose monohydrate [14431-43-7] and trehalose dihydrate [6138-23-4], as well as standard muscle tissue. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7COA of Formula: C6H14O7).

(2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7) belongs to tetrahydropyran derivatives. Numerous natural products have tetrahydropyran skeleton as the building block for designing new natural products and their derivatives e.g. aplysiatoxins, avermectins, oscillatoxins, talaromycins, latrunculins and acutiphycins. 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: C6H14O7

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

Linchpin Construction of Unsymmetrical 1,4-Alkynediols was written by Taber, Douglass F.;Storck, Pierre H.. And the article was included in Journal of Organic Chemistry in 2002.Recommanded Product: 13417-49-7 This article mentions the following:

Unsym. 1,4-alkynediols such as I are prepared by the coupling of trimethylsilylacetylene with two different aldehydes or ketones. Lithiation of trimethylsilylacetylene followed by addition of one aldehyde or ketone generates a lithium alkoxide; treatment with methyllithium removes the trimethylsilyl protecting group to generate a alkynyllithium which can add to a second aldehyde or ketone to give 1,4-alkynediols after workup. The desilylation reaction occurs only in THF. Aldehydes are preferable to ketones as the substrates for the first addition reaction; substrates with groups sensitive to base, such as easily lithiated arenes, should be added last. I, prepared in 65% yield from trimethylsilyllithium, cyclopropanecarboxaldehyde, and a dihydrobenzofurancarboxaldehyde, is converted to the diketone II, a metabolite of a potent nonsteroidal antiinflammatory agent, in two steps by oxidation of I to a 1,4-alkynyldione followed by reduction of the triple bond with palladium and barium sulfate. In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Recommanded Product: 13417-49-7).

5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) belongs to tetrahydropyran derivatives. Dihydropyrans and tetrahydropyrans are examples of cyclic ethers widespread in nature. One classic procedure for the organic synthesis of tetrahydropyran is by hydrogenation of the 3,4-isomer of dihydropyran with Raney nickel.Recommanded Product: 13417-49-7

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

Exploring the chemical space for freeze-drying excipients was written by Meng-Lund, Helena;Holm, Tobias Palle;Poso, Antti;Jorgensen, Lene;Rantanen, Jukka;Grohganz, Holger. And the article was included in International Journal of Pharmaceutics (Amsterdam, Netherlands) in 2019.Product Details of 14431-43-7 This article mentions the following:

Commonly, a limited number of generally accepted bulking agents and lyoprotectants are used for freeze-drying; predominantly mannitol, glycine, sucrose and trehalose. The purpose of this study was to combine a theor. approach using mol. descriptors with a large scale exptl. screening to evaluate the suitability of a broad range of excipients for freeze-drying. A large selection of sugars, polyols and amino acids was characterized by modulated differential scanning calorimetry (mDSC) and X-ray powder diffraction (XRPD) after well-plate based freeze-drying. The calculated mol. descriptors were investigated with both hierarchical cluster anal. and principal component anal. A clear clustering of the excipients according to the size-related and weight-related descriptors was observed; however other relevant descriptors could also be identified. From a practical perspective, a trend was observed with regard to a higher likelihood for amorphization and a higher glass transition temperature of the maximally freeze-concentrated solution with increasing mol. size. A translation of the mol. descriptors on pharmaceutical performance was more successful for lyoprotectants than for bulking agents. Addnl., in the course of the exptl. screening, several new potential bulking agents and lyoprotectants were identified. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7Product Details of 14431-43-7).

(2S,3R,4S,5S,6R)-6-(Hydroxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetraol hydrate (cas: 14431-43-7) belongs to tetrahydropyran derivatives. Tetrahydropyrans are also used as important solvents, as chemical intermediate and as monomer for ring-opening polymerization. The most notable anticancer agent, bryostatin, and eribulin are marine macrolides having intriguing tetrahydropyran and furan motif. Product Details of 14431-43-7

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

A new proof of structure of the cyclic dimers of α,β-ethylenic hydrocarbons was written by Dumas, Gerard;Rumpf, Paul. And the article was included in Compt. rend. in 1956.Recommanded Product: 13417-49-7 This article mentions the following:

Acrolein was dimerized in dilute HCl to 3-formyl-5,6-dihydro-α-pyran which gave a 78% yield of the corresponding acid, m. 83-4°, upon Ag₂O oxidation. Reduction of the acid with Raney Ni at 120 atm. and 100° gave tetrahydropyran-3-carboxylic acid (I), b₁₂ 136-7°; anilide, m. 131°. The dimer from the diene synthesis was reduced using Pt black, and the resulting formyltetrahydropyran treated with aqueous Ag₂O to give a tetrahydropyrancarboxylic acid (II), b₁₂ 126-7°; anilide, m. 122-3°. Ionization constants of II and I are 3.80 (20°) and 4.40 (18°), resp. These differences are taken as proof that the carbonyl group in the acrolein dimer from the diene synthesis is in the α-position so that II is tetrahydropyran-2-carboxylic acid. In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Recommanded Product: 13417-49-7).

5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) 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. The most notable anticancer agent, bryostatin, and eribulin are marine macrolides having intriguing tetrahydropyran and furan motif. Recommanded Product: 13417-49-7

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

Structure-Based Design of Selective β-Site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) Inhibitors: Targeting the Flap to Gain Selectivity over BACE2 was written by Fujimoto, Kazuki;Matsuoka, Eriko;Asada, Naoya;Tadano, Genta;Yamamoto, Takahiko;Nakahara, Kenji;Fuchino, Kouki;Ito, Hisanori;Kanegawa, Naoki;Moechars, Diederik;Gijsen, Harrie J. M.;Kusakabe, Ken-ichi. And the article was included in Journal of Medicinal Chemistry in 2019.Safety of Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate This article mentions the following:

BACE1 inhibitors hold potential as agents in disease-modifying treatment for Alzheimer’s disease. BACE2 cleaves the melanocyte protein PMEL in pigment cells of the skin and eye, generating melanin pigments. This role of BACE2 implies that nonselective and chronic inhibition of BACE1 may cause side effects derived from BACE2. Herein, we describe the discovery of potent and selective BACE1 inhibitors using structure-based drug design. We targeted the flap region, where the shape and flexibility differ between these enzymes. Anal. of the cocrystal structures of an initial lead 8 prompted us to incorporate spirocycles followed by its fine-tuning, culminating in highly selective compounds 21 and 22. The structures of 22 bound to BACE1 and BACE2 revealed that a relatively high energetic penalty in the flap of the 22-bound BACE2 structure may cause a loss in BACE2 potency, thereby leading to its high selectivity. These findings and insights should contribute to responding to the challenges in exploring selective BACE1 inhibitors. In the experiment, the researchers used many compounds, for example, Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2Safety of Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate).

Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate (cas: 103260-44-2) belongs to tetrahydropyran derivatives. In organic synthesis, the 2-tetrahydropyranyl group is used as a protecting group for alcohols. One classic procedure for the organic synthesis of tetrahydropyran is by hydrogenation of the 3,4-isomer of dihydropyran with Raney nickel.Safety of Ethyl 2-(tetrahydro-2H-pyran-4-yl)acetate

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