Month: November 2022

Bolitt, Veronique published the artcileTriphenylphosphine hydrobromide: a mild and efficient catalyst for tetrahydropyranylation of tertiary alcohols, Category: tetrahydropyran, the publication is Tetrahedron Letters (1988), 29(36), 4583-6, database is CAplus.

PPh₃.HBr is a convenient and highly effective catalyst for tetrahydropyranylation of tertiary alcs. with dihydropyran in CH₂Cl₂ at ambient temperature Thus EtMe₂COH gave 92% tetrahydropyranyl ether.

Tetrahedron Letters published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Category: tetrahydropyran.

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

Radchenko, Dmytro S. published the artcileAn easy synthesis of α-trifluoromethyl-amines from aldehydes or ketones using the Ruppert-Prakash reagent, Application In Synthesis of 1354961-50-4, the publication is Tetrahedron Letters (2013), 54(14), 1897-1898, database is CAplus.

A small library of structurally diverse primary amines bearing a geminal CF₃ group was synthesized on a preparative scale. The synthesis starts with an aldehyde or ketone that reacts with benzylamine yielding the corresponding imine. The latter is then trifluoromethylated with Me₃SiCF₃ under acidic conditions to give a benzylalkylamine. In the last step the Pd-mediated hydrogenation of the benzylalkylamines furnishes the title compounds All synthetic steps are high-yielding; neither the isolation of the intermediates nor the chromatog. purification of the products is necessary.

Tetrahedron Letters published new progress about 1354961-50-4. 1354961-50-4 belongs to tetrahydropyran, auxiliary class Trifluoromethyl,Tetrahydropyran,Fluoride,Salt,Amine, name is 4-(Trifluoromethyl)tetrahydro-2H-pyran-4-amine hydrochloride, and the molecular formula is C6H11ClF3NO, Application In Synthesis of 1354961-50-4.

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

Kurek-Tyrlik, Alicja published the artcileA synthesis of 17-epi-calcidiol, Related Products of tetrahydropyran, the publication is Tetrahedron Letters (2004), 45(40), 7479-7482, database is CAplus.

The first synthetic approach to 17-epi-calcidiol (I) and congeners is presented. Key steps of the synthesis involve Pd-catalyzed reaction of the androst-16-ene derivative II with alkyl diazoacetates producing the resp. 16,17-cyclopropano derivatives, and lithium in liquid ammonia reduction leading to 17α-pregnane-20-carboxylic acid derivatives The side chain was attached in a known manner.

Tetrahedron Letters published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Related Products of tetrahydropyran.

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

Kurek-Tyrlik, Alicja published the artcileSynthesis of 17-epi-Calcitriol from a Common Androstane Derivative, Involving the Ring B Photochemical Opening and the Intermediate Triene Ozonolysis, Synthetic Route of 27943-46-0, the publication is Journal of Organic Chemistry (2005), 70(21), 8513-8521, database is CAplus and MEDLINE.

An efficient synthesis of 17-epi-calcitriol (I), an epimer of natural hormone, via 17-epi-cholesterol II is described. Synthesis of II includes palladium-catalyzed cyclopropanation of the common androstane derivative III with an alkyl diazoacetate, reductive fission of the less shielded side of cyclopropane carboxylic acid esters, oxidation of the products into acid, and alkylation of ester. Photolysis of 7,8-dehydro-17-epi-25-hydroxycholesterol and consecutive thermal rearrangement gave a mixture of several products that was subjected to ozonolysis to provide, after chromatog., hydroxy ketone IV. The silyl derivative of IV was coupled with the resp. ring A building block.

Journal of Organic Chemistry published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Synthetic Route of 27943-46-0.

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

Kessberg, Anton published the artcileEnantioselective Synthesis of 2′- and 3′-Substituted Natural Flavans by Domino Asymmetric Transfer Hydrogenation/Deoxygenation, Recommanded Product: 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, the publication is Organic Letters (2016), 18(24), 6500-6503, database is CAplus and MEDLINE.

A concise and highly enantioselective synthesis of the natural flavans kazinol U and (2S)-7,3′-dihydroxy-4′-methoxyflavan is reported for the first time. The key transformation is a single-step conversion of a racemic flavanone to a flavan by means of an asym. transfer hydrogenation/deoxygenation cascade with kinetic resolution

Organic Letters published new progress about 69097-99-0. 69097-99-0 belongs to tetrahydropyran, auxiliary class Other Aliphatic Heterocyclic,Benzene,Phenol,Ether,Inhibitor, name is 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, and the molecular formula is C16H14O6, Recommanded Product: 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one.

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

Baroudi, Abdulkader published the artcileConformationally Gated Fragmentations and Rearrangements Promoted by Interception of the Bergman Cyclization through Intramolecular H-Abstraction: A Possible Mechanism of Auto-Resistance to Natural Enediyne Antibiotics?, Safety of 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, the publication is Journal of the American Chemical Society (2010), 132(3), 967-979, database is CAplus and MEDLINE.

A variety of fragmentations and rearrangements can follow Bergman cyclization in enediynes equipped with acetal rings mimicking the carbohydrate moiety of natural enediyne antibiotics of the esperamicin and calicheamicin families. In the first step of all these processes, intramol. H-atom abstraction efficiently intercepts the p-benzyne product of the Bergman cyclization through a six-membered TS and transforms the p-benzyne into a new more stable radical. Depending on the substitution pattern and reaction conditions, this radical follows four alternative paths: (a) abstraction of an external hydrogen atom, (b) O-neophyl rearrangement which transposes O- and C-atoms of the substituent, (c) fragmentation of the O-C bond in the acetal ring, or (d) fragmentation with elimination of the appended acetal moiety as a whole. Experiments with varying concentrations of external H-atom donor (1,4-cyclohexadiene) were performed to gain further insight into the competition between intermol. H-abstraction and the fragmentations. The Thorpe-Ingold effect in gem-di-Me substituted enediynes enhances the efficiency of fragmentation to the extent where it cannot be prevented even by a large excess of external H-atom donor. These processes provide insight into a possible mechanism of unusual fragmentation of esperamicin A₁ upon its Bergman cycloaromatization and lay foundation for a new approach for the conformational control of reactivity of these natural antitumor antibiotics. Such an approach, in conjunction with supramol. constraints, may provide a plausible mechanism for resistance to enediyne antibiotics by the enediyne-producing microorganisms.

Journal of the American Chemical Society published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, Safety of 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran.

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

Conrads, Martin published the artcileCycloadditions. 32. Convenient methods for the preparation of sulfur substituted allenecarboxylates, COA of Formula: C10H16O2, the publication is Synthesis (1991), 11-14, database is CAplus.

2-Sulfinyl- and 2-sulfonylallenecarboxylates, as new 1,1-diacceptor substituted allenes, were prepared starting from Me 4-hydroxy-4-methyl-2-pentynoate by a [2,3]-sigmatropic rearrangement. The sulfoxides could be reduced to the corresponding allenyl sulfides. A 2(5H)-furanone derivative was prepared by a side reaction.

Synthesis published new progress about 27943-46-0. 27943-46-0 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Alkynyl,Ether, name is 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, and the molecular formula is C10H16O2, COA of Formula: C10H16O2.

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

Draganov, Dragomir I. published the artcileExtensive metabolism and route-dependent pharmacokinetics of bisphenol A (BPA) in neonatal mice following oral or subcutaneous administration, Computed Properties of 267244-08-6, the publication is Toxicology (2015), 168-178, database is CAplus and MEDLINE.

Orally administered bisphenol A (BPA) undergoes efficient first-pass metabolism to produce the inactive conjugates BPA-glucuronide (BPA-G) and BPA-sulfate (BPA-S). This study was conducted to evaluate the pharmacokinetics of BPA, BPA-G and BPA-S in neonatal mice following the administration of a single oral or s.c. (SC) dose. This study consisted of 3 phases: mass-balance phase in which ED delivery procedures for oral or SC administration of ³H-BPA to postnatal day three (PND3) mice were developed; pharmacokinetic phase during which systemic exposure to total ³H-BPA-derived radioactivity in female PND3 mice was established; and metabolite profiling phase in which 50 female PND3 pups received either a single oral or SC dose of ³H-BPA. Blood was collected from 5 pups/route/time-point at various times post-dosing, the blood plasma samples were pooled by group, and time-point and samples were profiled by HPLC with fraction collection. Fractions were analyzed for total radioactivity and data used to reconstruct radiochromatograms and to integrate individual peaks. The identity of the BPA, BPA-G, and BPA-S peaks was confirmed using authentic standards and LC-MS/MS anal. The result of this study revealed that female PND3 mice have the capacity to metabolize BPA to BPA-G, BPA-S and other metabolites after both routes of administration. Systemic exposure to free BPA is route-dependent as the plasma concentrations were lower following oral administration compared to SC injection.

Toxicology published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Computed Properties of 267244-08-6.

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

Deka, Nabajyoti published the artcileMicrowave mediated solvent-free acetylation of deactivated and hindered phenols, Category: tetrahydropyran, the publication is Green Chemistry (2001), 3(5), 263-264, database is CAplus.

Deactivated and sterically hindered phenols have been acetylated with acetic anhydride under microwave irradiation using iodine as catalyst in an eco-friendly process. The reaction was carried out under solvent-free conditions and the acetates were obtained in nearly quant. yields with dramatic reduction of reaction time compared to standard oil-bath heating.

Green Chemistry published new progress about 69097-99-0. 69097-99-0 belongs to tetrahydropyran, auxiliary class Other Aliphatic Heterocyclic,Benzene,Phenol,Ether,Inhibitor, name is 5,7-Dihydroxy-2-(3-hydroxy-4-methoxyphenyl)chroman-4-one, and the molecular formula is C16H14O6, Category: tetrahydropyran.

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

Mazur, Christopher S. published the artcileHuman and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment, Product Details of C21H24O8, the publication is Toxicological Sciences (2012), 128(2), 317-325, database is CAplus and MEDLINE.

Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physiol. processes, and their enzyme localization (apical vs. basolateral) in the plasma membrane allows for different cellular efflux pathways. In this study, we utilized an ATPase assay to evaluate BPA and BPA-G as potential substrates for the human and rat ABC transporters: P-glycoprotein (MDR1), multidrug resistance-associated proteins (MRPs), and breast cancer-resistant protein (BCRP). Based on high ATPase activity, BPA is likely a substrate for rat mdr1b but not for human MDR1 or rat mdr1a. Results indicate that BPA is a potential substrate for rat mrp2 and human MRP2, BCRP, and MRP3. The metabolite BPA-G demonstrated the highest apparent substrate binding affinity for rat mrp2 and human MRP3 but appeared to be a nonsubstrate or potential inhibitor for human MRP2, MDR1, and BCRP and for rat mdr1a, mdr1b, and bcrp. Anal. of ABC transporter amino acid sequences revealed key differences in putative binding site composition that may explain substrate specificity. Collectively, these results suggest that in both rat and human, apical transporters efflux BPA into the bile and/or intestinal lumen. BPA-G would follow a similar pathway in rat; however, in human, due to the basolateral location of MRP3, BPA-G would likely enter systemic and portal blood supplies. These differences between human and rodent ABC transporters may have significant implications for interspecies extrapolation used in risk assessment.

Toxicological Sciences published new progress about 267244-08-6. 267244-08-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Chiral,Carboxylic acid,Benzene,Phenol,Alcohol,Ether,, name is (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, and the molecular formula is C21H24O8, Product Details of C21H24O8.

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