Category: tetrahydropyran

Salomon, Robert G. published the artcileTotal synthesis of spatol and other spatane diterpenes, Name: 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, the publication is Journal of the American Chemical Society (1991), 113(8), 3096-106, database is CAplus.

Total syntheses of three spatane diterpenes stoechospermol (I; R = CH₂CH₂CH:CMe₂ R¹ = H), 5(R),15(R),18-trihydroxyspata-13,16(E)-diene (I; R = R², R¹ = H) and (+)-spatol (I; R = R³, R¹ = H) were accomplished from a common intermediate, diol I (R = CH₂OH, R¹ = H). The total synthesis established as R the absolute configuration at the 15-position in I (R = R², R¹ = H). Novel stereospecific transformations of 2,3-epoxy-1,4-diols into vicinal diepoxides were demonstrated and exploited for assembling the sensitive allylic diepoxide in the side chain of spatol. This new synthetic model allows the conversion of both 1,2-threo-2,3-trans– and 1,2-erythro-2,3-trans-2,3-epoxy-1,4-diols into vicinal 1,2-cis-2,3-erythro-1,3-diepoxides. Unexpected stability toward hydroxide anion was found for the allylic diepoxide functional array. This observation provides presumptive evidence that acid catalysis is operative in the epoxide cleaving substitution reaction of spatol by the weakly nucleophilic chloride anion that gives chlorohydrin I (R = R⁴, R¹ = COC₆H₄Br-p). A proclivity for erythro-selective epoxidation of allylic silyl ethers was found. The utility of C-silyl substituents for reversing this stereoselectivity, i.e., favoring threo-selective epoxidation of allylic silyl ethers, was established.

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, Name: 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran.

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

Saalfrank, Rolf W. published the artcile1,3-Donor/donor-substituted allenes. VII. Allenecarboxanilides by transannulation or [2.3]/[3.3]-sigmatropic rearrangements – building blocks with versatile intra- and intermolecular synthetic potential, Related Products of tetrahydropyran, the publication is Chemische Berichte (1993), 126(3), 823-35, database is CAplus.

The reaction of 1,3-bis(alkylarylamino)-1,3-diethoxyallenes with disubstituted malonyl chlorides leads to N,N’-dialkyl-N,N’-diarylallene-1,1-dicarboxamides and 2H-pyran-2,4(3H)-diones, with a transallenation reaction being favored in the case of EtO(MePhN)C:C:C(NPhMe)OEt. Thermal tandem cyclization of (MePhNCO)₂C:C:C(C₆H₄CMe₃-4)₂ via 2-quinolone affords phenanthridone I. Thermally induced cyclization of the pyrandiones leads to 4-quinolones. 4-RC₆H₄SO₂CMe₂CCCONPh₂ (R = H, Me), on heating undergoes a [2,3]-sigmatropic rearrangement to 4-RC₆H₄SO₂C(CONPh₂):C:CMe₂. Reaction of HOCR¹₂CCCONPh₂ [II, R¹ = Me; R¹₂ = (CH₂)₅] with sulfenyl chlorides or chlorophosphines, followed by [2,3]-sigmatropic shift, affords N-phenyl-1-sulfinyl- and N-phenyl-1-phosphorylallene-1-carboxanilides, resp. Alkynyl ketene acetal intermediates are formed from II and orthoesters. Spontaneous [3,3]-sigmatropic rearrangement then gives N-phenylallene-1-carboxanilides. Intramol. Diels-Alder reaction of the allenecarboxanilides gives [2.2.2]bicycles.

Chemische Berichte 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

El Amin Zaid, Mohammed published the artcileSynthesis and chiral separation of some 4-thioflavones, Synthetic Route of 69097-99-0, the publication is Journal of Chromatographic Science (2021), 59(9), 856-862, database is CAplus and MEDLINE.

A thionation reaction was performed on some chiral flavanones using Lawesson’s reagent (LR) and leads to the formation of new chiral thiocarbonyl flavanes. LR in this thionation reaction with Hesperetin and Naringenin gives new flavan-4-thiones with yields ranged between 41 and 52%. Based on the Wittig reaction principle, LR is currently the most widely used reagent for this type of reaction. Enantiomeric separation by high-performance liquid chromatog. methods was then set-up using three different polysaccharide-based chiral stationary phases (CSPs). Chiral separations were successfully accomplished with high resolution (1.22 ≤ Rs ≤ 5.23). The chiral discrimination mechanism(s) between the analytes under study, mobile phase, and the CSPs were discussed.

Journal of Chromatographic Science 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, Synthetic Route of 69097-99-0.

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

Gorecki, Sebastien published the artcileHuman health risks related to the consumption of foodstuffs of animal origin contaminated by bisphenol A, Safety of (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Food and Chemical Toxicology (2017), 333-339, database is CAplus and MEDLINE.

Bisphenol A (BPA) is used in a wide variety of products and objects for consumers use (digital media such as CD’s and DVD’s, sport equipment, food and beverage containers, medical equipment). For humans, the main route of exposure to BPA is food. Based on previous estimates, almost 20% of the dietary exposure to BPA in the French population would be from food of animal origin. However, due to the use of composite samples, the source of the contamination had not been identified. Therefore, 322 individual samples of non-canned foods of animal origin were collected with the objectives of first updating the estimation of the exposure of the French population and second identifying the source of contamination of these foodstuffs using a specific anal. method. Compared to previous estimates in France, a decline in the contamination of the samples was observed, in particular with regard to meat. The estimated mean dietary exposures ranged from 0.048 to 0.050 μg (kg bw)^-1 d^-1 for 3-17 yr children and adolescents, from 0.034 to 0.035 μg (kg bw)^-1 d^-1 for adults and from 0.047 to 0.049 μg (kg bw)^-1 d^-1 for pregnant women. The contribution of meat to total dietary exposure of pregnant women, adults and children was up to three times lower than the previous estimates Despite this downward trend in contamination, the toxicol. values were observed to have been exceeded for the population of pregnant women. With the aim of acquiring more knowledge about the origin the potential source(s) of contamination of non-canned foods of animal origin, a specific anal. method was developed to directly identify and quantify the presence of conjugated BPA (BPA-monoglucuronide, BPA-diglucuronide and sulfate forms) in 50 samples. No conjugated forms of BPAs were detected in the analyzed samples, indicating clearly that BPA content in animal food was not due to metabolism but arise post mortem in food. This contamination may occur during food production However, despite extensive sampling performed in several different shops (butcheries, supermarkets …. ) and in different conditions (fresh, prepared, frozen …), the source(s) of the contamination could not be specifically identified.

Food and Chemical 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, Safety of (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

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

Provencher, Gilles published the artcileDetermination of bisphenol A, triclosan and their metabolites in human urine using isotope-dilution liquid chromatography-tandem mass spectrometry, Product Details of C21H24O8, the publication is Journal of Chromatography A (2014), 97-104, database is CAplus and MEDLINE.

Bisphenol A (BPA) and triclosan (TCS) are ubiquitous environmental phenols exhibiting endocrine disrupting activities that may be involved in various health disorders in humans. There is a need to measure sep. free forms and conjugated metabolites because only the former are biol. active. The authors have developed sensitive methods using isotope-dilution liquid chromatog.-tandem mass spectrometry for individual measurements of free BPA and TCS as well as their metabolites, BPA glucuronide (BPAG), BPA monosulfate (BPAS), BPA disulfate (BPADS), TCS glucuronide (TCSG) and TCS sulfate (TCSS) in urine. Comparative analyses of urine samples from 46 volunteers living in the Quebec City area using the new methods and a GC-MS/MS method previously used in the authors’ laboratory revealed very strong correlations for total BPA (Spearman’s r_s = 0.862) and total TCS concentrations (r_s = 0.942). Glucuronide metabolites were the most abundant BPA and TCS species in urine samples (>94% of total urinary concentrations). Unconjugated TCS concentrations represented a small proportion of total TCS species (median = 1.6%) but its concentration was likely underestimated due to losses by adsorption to the surface of polypropylene tubes used for sample storage. To the authors’ knowledge, the authors are the first to report levels of free, sulfated and glucuronidated TCS levels in human urine.

Journal of Chromatography A 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

Kurebayashi, Hideo published the artcileDisposition of a Low Dose of ¹⁴C-Bisphenol A in Male Rats and Its Main Biliary Excretion as BPA Glucuronide, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid, the publication is Toxicological Sciences (2003), 73(1), 17-25, database is CAplus and MEDLINE.

Bisphenol A (BPA) is a weak xenoestrogen mass-produced with potential human exposure. The disposition of bisphenol A in male Fischer-344 (F344) rats dosed orally (100 or 0.10 mg/kg) or i.v. (0.10 mg/kg) was determined Smaller amounts of the dose appeared in the urine. The main excretion route was feces in rats irresp. of dose and administration route. The biliary excretion during 6 h was 58-66% after iv dosing and 45-50% after oral dosing at 0.10 mg ¹⁴C-BPA/kg. Toxicokinetic parameters obtained from ¹⁴C-BPA-derived radioactivity in blood were the terminal elimination half-life, t_1/2β = 39.5 h, and total body clearance, CL_tot = 0.52 l/h/kg after iv dosing of 0.10 mg ¹⁴C-BPA/kg to male rats. The blood concentration reached its maximum of 5.5 ng-eq/mL at 0.38 h after oral dose. AUC_(0-6 h), AUC_(0-48 h), and AUC_inf of ¹⁴C-BPA-derived radioactivity, were 34, 118, and 192 ng-eqh/mL for the iv dose and 18, 102, and 185 ng-eqh/mL for the oral dose, resp. The oral bioavailability of F_(0-6 h), F_(0-48 h), and F_inf were 0.54, 0.86, and 0.97, resp. The ¹⁴C-BPA-derived radioactivity was strongly bound to plasma protein (free fraction, fu = 0.046) and preferentially distributed to the plasma with a blood/plasma ratio of 0.67. From the bile of male rats orally dosed at 100 mg/kg, we have isolated and characterized BPA glucuronide (BPA-gluc) by ESI/MS, ¹H and ¹³C NMR spectroscopy. HPLC anal. showed that BPA-gluc was the predominant metabolite in bile and urine. Unchanged BPA was mostly detected in feces. These results suggest that BPA is mainly metabolized to BPA-gluc and excreted into feces through the bile and subject to enterohepatic circulation in rats irresp. of dose and administration route.

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, Recommanded Product: (2S,3S,4S,5R,6S)-3,4,5-Trihydroxy-6-(4-(2-(4-hydroxyphenyl)propan-2-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid.

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

Ontoria, Jesus M. published the artcileCombined Peptide and Small-Molecule Approach toward Nonacidic THIQ Inhibitors of the KEAP1/NRF2 Interaction, Product Details of C10H16O2, the publication is ACS Medicinal Chemistry Letters (2020), 11(5), 740-746, database is CAplus and MEDLINE.

The NRF2-ARE pathway is an intrinsic mechanism of defense against oxidative stress. Inhibition of the interaction between NRF2 and its main neg. regulator KEAP1 is an attractive strategy toward neuroprotective agents. We report here the identification of nonacidic tetrahydroisoquinolines (THIQs) that inhibit the KEAP1/NRF2 protein-protein interaction. Peptide SAR at one residue is utilized as a tool to probe structural changes within a specific pocket of the KEAP1 binding site. We used structural information from peptide screening at the P2 pocket, noncovalent small-mols. inhibitors, and the outcome from an explorative SAR at position 5 of THIQs to identify a series of neutral THIQ analogs that bind to KEAP1 in the low micromolar range. These analogs establish new H-bond interactions at the P3 and P2 pockets allowing the replacement of the carboxylic acid functionality by a neutral primary carboxamide. X-ray crystallog. studies reveal the novel binding mode of these mols. to KEAP1.

ACS Medicinal Chemistry 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, Product Details of C10H16O2.

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