Month: November 2022

Liao, Chunyang published the artcileDetermination of Free and Conjugated Forms of Bisphenol A in Human Urine and Serum by Liquid Chromatography-Tandem Mass Spectrometry, Computed Properties of 267244-08-6, the publication is Environmental Science & Technology (2012), 46(9), 5003-5009, database is CAplus and MEDLINE.

Exposure of humans to bisphenol A (BPA), a widely used industrial chem., is well-known. In humans and animals, conjugation of BPA mol. with glucuronide or sulfate is considered as a mechanism for detoxification. Nevertheless, very few studies have directly measured free, conjugated (e.g., glucuronidated), and substituted (e.g., chlorinated) forms of BPA in human specimens. In this study, free, conjugated (BPA glucuronide or BPAG and BPA disulfate or BPADS), and substituted (chlorinated BPA; mono- [BPAMC], di-[BPADC], and trichloride [BPATrC]) forms of BPA were determined in human urine and serum samples, using solid-phase extraction (SPE) and liquid chromatog.-tandem mass spectrometry (LC-MS/MS) techniques. The instrumental calibration for each of the target compounds ranged from 0.01 to 100 ng/mL and showed excellent linearity (r > 0.99). The limits of quantification (LOQs) were 0.01 ng/mL for free BPA and 0.05 ng/mL for the conjugated and substituted BPA. Resp. recoveries of the six target compounds spiked into water blanks and sample matrixes (urine and serum), and passed through the entire anal. procedure, were 96 ± 14% and 105 ± 18% (mean ± SD) for urine samples and 87 ± 8% and 80 ± 13% for serum samples. The optimal recoveries of BPAG and BPADS in the anal. procedure indicted that no deconjugation occurred during the SPE procedure. The method was applied to measure six target chems. in urine and serum samples collected from volunteers in Albany, New York. BPA and its derivatives were found in urine samples at concentrations ranging from < LOQ to a few tens of ng/mL. In serum, free and conjugated BPA were detected at sub ng/mL concentrations, whereas BPA chlorides were not detected. The urine and serum samples were also analyzed by enzymic deconjugation and liquid-liquid extraction (LLE) for the determination of total BPA, and the results were compared with those measured by the SPE method. To our knowledge, this is the first report on the occurrence of BPAG and BPADS in human serum.

Environmental Science & Technology 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

Boutier, Audrey published the artcilePd-Catalyzed Asymmetric Synthesis of N-Allenyl Amides and Their Au-Catalyzed Cycloisomerizative Hydroalkylation: A New Route Toward Enantioenriched Pyrrolidones, HPLC of Formula: 27943-46-0, the publication is Chemistry – A European Journal (2012), 18(13), 3840-3844, S3840/1-S3840/66, database is CAplus and MEDLINE.

Au-catalyzed cycloisomerizative hydroalkylation of N-allenyl amides affords regioselectively 4-vinyl-γ-lactams. This transformation is stereospecific and takes place with total axis-to-center chirality transfer. The required enantioenriched N-allenyl amide is successfully obtained from Pd-catalyzed dynamic kinetic asym. allenylic amination. Overall this process is as follows: N-benzyl-2,2,2-trifluoroacetamide + (±)-n-pentyl-CH:C:CHCH₂OAc → I (R = COCF₃ e.r. 82:18) → I (R = COCH₂COMe) → II (e.r. 81:19).

Chemistry – A European Journal 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, HPLC of Formula: 27943-46-0.

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

Kulandai Raj, Antony Sekar published the artcileGold-Catalyzed N,O-Functionalizations of 6-Allenyl-1-ynes with N-Hydroxyanilines To Construct Benzo[b]-azepin-4-one Cores, Related Products of tetrahydropyran, the publication is Organic Letters (2017), 19(19), 5340-5343, database is CAplus and MEDLINE.

Gold-catalyzed reactions of 6-allen-1-ynes with N-hydroxyanilines afford thermally stable benzoazepin-4-ones in anti-selectivity; these anti-configured products are easily isomerized to their syn-isomers on a silica column. The mechanism of reactions likely involve initial nitrone/allene cycloadditions, followed by skeletal rearrangement of resulting intermediates.

Organic 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

Murakami, Masahiro published the artcileMolybdenum-Catalyzed Ring-Closing Metathesis of Allenynes, Product Details of C10H16O2, the publication is Organic Letters (2005), 7(18), 3953-3956, database is CAplus and MEDLINE.

A ring-closing metathesis reaction of allenynes I [X = 4-MeC₆H₄SO₂N; PhCH₂N, (MeO₂C)₂C, (EtO₂C)₂C; R¹ = H, Me; R² = Me, Me₂CH; R³ = H, Me, Et, Ph; R²R³ = (CH₂)₅] occurred at room temperature in the presence of a molybdenum alkylidene complex to give ring-closed vinylallenes II. The vinylallene skeletons were constructed by a metathesis-type reaction between the alkyne moiety and the proximal carbon-carbon double bond of the allene moiety.

Organic 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

Kim, Eun-Hye published the artcileExposure to phthalates and bisphenol A are associated with atopic dermatitis symptoms in children: a time-series analysis, 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 Environmental Health (London, United Kingdom) (2017), 24/1-24/8, database is CAplus and MEDLINE.

Background: Despite increasing evidence on the relationship between exposure to phthalates and bisphenol A with allergies and asthma, reports on atopic dermatitis (AD) with these chems. are few. We assessed the association between AD symptoms and the exposure to phthalates and bisphenol A and in children. Methods: We surveyed 18 boys with AD (age 3-7 years) in a day care center in Seoul between May 2009 and Apr. 2010. AD symptoms were recorded by using a daily symptom diary. We collected 460 series of pooled urine twice a day, in the morning and afternoon, over 230 working days and measured the concentrations of mono-2-ethyl-5-oxohexyl phthalate (5-oxo-MEHP), mono-2-ethyl-5-hydroxyhexyl phthalate (5-OH-MEHP), mono-iso-Bu phthalate (MnBP) and bisphenol A glucuronide (BPAG) in the pooled urine. Logistic regression was used for statistical anal. Results: Most phthalate metabolite levels were higher in the morning than in the afternoon (p<0.0001). There was seasonal variation in the levels of phthalates and bisphenol A metabolites. Levels of 5-OH-MEHP, MnBP, and BPAG were highest in summer (p<0.0001). Manifestation of AD symptoms was associated with an increase in urinary levels of MnBP (adjusted odds ratio, aOR = 2.85, 95% CI: 1.12-7.26 per 1μg/L of MnBP) and BPAG (aOR = 1.79, 95% CI: 0.91-3.52 per 1μg/L BPAG) on the same day. The levels of MnBP and BPAG in the previous day increased AD symptoms (aOR = 2.74, 95% CI: 1.21-6.20, for 1μg/L of MnBP and aOR = 2.01, 95% CI: 1.08-3.74 for 1μg/L BPAG). Conclusion: Our results suggest that exposure to phthalates and bisphenol A is associated with aggravation of AD symptoms in children.

Environmental Health (London, United Kingdom) 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

Phillips, Catherine published the artcileUseful route to 1,6-dioxaspiro[4.4]nonane and 1,6-dioxaspiro[4.5]decane derivatives, Related Products of tetrahydropyran, the publication is Journal of Organic Chemistry (1980), 45(10), 1920-4, database is CAplus.

A wide variety of 1,6-dioxaspiro[4.4]nonanes, e.g. I, and 1,6-dioxaspiro[4.5]decanes, e.g. II, including certain insect pheromones, can be conveniently prepared by reaction of the Li salts of protected alkynols with equimolar amounts of lactones followed by hydrogenation and acid-catalyzed deprotection and cyclization. Alkynols are satisfactorily protected either as their tetrahydropyranol or as their 1-ethoxyethyl ethers; intermediates need not be isolated. Yields are variable, but products are readily obtainable in high purity regardless of yield.

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, Related Products of tetrahydropyran.

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

Sogo, Hideyuki published the artcileRhenium(I)-Catalyzed Generation of α,β-Unsaturated Carbene Complex Intermediates from Propargyl Ethers for the Preparation of Cycloheptadiene Derivatives, Computed Properties of 27943-46-0, the publication is Angewandte Chemie, International Edition (2016), 55(34), 10057-10060, database is CAplus and MEDLINE.

The rhenium(I)-catalyzed generation of α,β-unsaturated carbene complex intermediates from easily available propargyl ethers was achieved for the concise construction of cycloheptadiene derivatives through the formal [4+3] cycloaddition reaction with siloxydienes.

Angewandte Chemie, International Edition 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 C12H15NO, Computed Properties of 27943-46-0.

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

Ismailov, Ismail E. published the artcileBifunctionalized allenes. Part XIII. A convenient and efficient method for regioselective synthesis of phosphorylated α-hydroxyallenes with protected and unprotected hydroxy group, HPLC of Formula: 27943-46-0, the publication is Molecules (2014), 19(5), 6309-6329, 21 pp., database is CAplus and MEDLINE.

The paper describes a convenient and efficient method for regioselective synthesis of phosphorylated α-hydroxyallenes using an atom economical [2,3]-sigmatropic rearrangement of intermediate propargyl phosphites or phosphinites. These can be readily prepared via reaction of protected alkynols with di-Me chlorophosphite or chlorodiphenyl phosphine resp. in the presence of a base.

Molecules 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, HPLC of Formula: 27943-46-0.

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

Narukawa, Junichi published the artcileGlucuronidation of 1-naphthol and excretion into the vein in perfused rat kidney, Related Products of tetrahydropyran, the publication is Drug Metabolism and Disposition (2004), 32(7), 758-761, database is CAplus and MEDLINE.

UDP-glucuronosyltransferase is expressed in the proximal convoluted tubular cells of rat kidney. Kidney perfusion with a Krebs-Henseleit buffer containing 1-naphthol was performed to estimate the dynamics and disposition of the glucuronide conjugate formed in the epithelial cells of the renal tubules. When 1-naphthol was injected into the renal artery, and the perfusate from the renal vein was returned to a reservoir and recirculated through the kidney preparation (recirculating perfusion), most of the 1-naphthol was immediately excreted into the vein as a glucuronide conjugate and its concentration increased rapidly. In contrast, the 1-naphthol glucuronide appeared more slowly in the urine. 1-Naphthol was also injected during the initial 5 min of perfusion under single-pass perfusion conditions (single-pass perfusion) in situ, and the metabolite and parent compound in the venous perfusate and in urine were assayed. Under this condition, most of the 1-naphthol glucuronide was excreted into the renal vein, and not urine. Phenol UDP-glucuronosyltransferase was highly induced in the rat kidney by β-naphthoflavone treatment. Moreover, the amount of 1-naphthol glucuronide excreted in the renal vein was increased 2.7-fold in the perfused kidney of β-naphthoflavone-treated rats, but the amount in the urine was not significantly increased under single-pass perfusion conditions. These results indicate that the kidney can glucuronidate phenolic xenobiotics in epithelial cells of the tubules and excrete the resultant glucuronide into the renal vein.

Drug Metabolism and Disposition 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, Related Products of tetrahydropyran.

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

Hirano, Yutaka published the artcileSteroid studies. 77. Synthesis of (22R- and (22S)-22,25-dihydroxyvitamin D₃ and determination of their biological activity, Name: 2-((2-Methylbut-3-yn-2-yl)oxy)tetrahydro-2H-pyran, the publication is Chemical & Pharmaceutical Bulletin (1981), 29(8), 2254-60, database is CAplus and MEDLINE.

Bisnorcholenal 3-tetrahydropyranyl ether was coupled with the lithium acetylide derived from 2-methyl-3-butyn-2-ol tetrahydropyranyl ether to give a 74% yield of a 1:1 mixture of the cholest-5-ene-3β,22,25-trihydroxy-23-yne 3,25-bis(tetrahydropyranyl)ethers. After resolution of the C-22 epimers and determination of their configurations, both isomers were converted into 22,25-dihydroxycholesterol 3,22-diacetates and into 25-hydroxy-22-methoxycholesterol 3-acetates. These compounds were converted to (22R)- and (22S)-22,25-dihydroxyvitamin D₃ and to 25-hydroxy-22-methoxyvitamin D₃. Biol. activity of these vitamin D₃ derivatives were determined

Chemical & Pharmaceutical Bulletin 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