نتایج جستجو برای: 14 dioxane
تعداد نتایج: 360389 فیلتر نتایج به سال:
The title compound, C(24)H(40)O(2), lies on an inversion center with a half-mol-ecule in the asymmetric unit. The central dioxane ring adopts a chair conformation. The four-membered ring is slightly puckered with a butterfly angle of 13.50 (14)°.
In the title mol-ecule, C(16)H(14)Cl(2)O(4), the 1,3-dioxane and cyclo-hexane rings exhibit distorted boat and chair conformations, respectively. In the crystal, a pair of weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into an inversion dimer.
A microcosm study was conducted to assess two biostimulation strategies (relative to natural attenuation) to bioremediate 1,4-dioxane contamination at a site in west Texas. Dioxane concentrations were relatively low (<300 μg/L), which represents a potential challenge to sustain and induce specific degraders. Thus, biostimulation was attempted with an auxiliary substrate known to induce dioxane-...
The x-ray crystal structure of the serine protease subtilisin Carlsberg in anhydrous dioxane has been determined to 2.6-A resolution. The enzyme structure is found to be nearly indistinguishable from the structures previously determined in water and acetonitrile. Small changes in the side-chain conformations between the dioxane and water structures are of the same magnitude as those observed be...
THE ASYMMETRIC UNIT OF THE TITLE COMPOUND [SYSTEMATIC NAME: 5-(1-bromo-prop-2-en-1-yl)-5-sec-butyl-pyrimidine-2,4,6-trione 1,4-dioxane hemisolvate], C(11)H(15)BrN(2)O(3)·0.5C(4)H(8)O(2), contains one half-mol-ecule of 1,4-dioxane and one mol-ecule of butallyl-onal, with an almost planar barbiturate ring [largest deviation from the mean plane = 0.049 (5) Å]. The centrosymmetric dioxane mol-ecule...
In this research, the characteristics of CMP dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13C NMR spectroscopy and DFRC degradation procedure. The results indicated that the main structural units in lignins are phenyl propane skeletons b...
A bacterium designated Pseudonocardia sp. strain ENV478 was isolated by enrichment culturing on tetrahydrofuran (THF) and was screened to determine its ability to degrade a range of ether pollutants. After growth on THF, strain ENV478 degraded THF (63 mg/h/g total suspended solids [TSS]), 1,4-dioxane (21 mg/h/g TSS), 1,3-dioxolane (19 mg/h/g TSS), bis-2-chloroethylether (BCEE) (12 mg/h/g TSS), ...
Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R)-dimethyl tartrate. Using standard phosphorimidite methodology, the adenine analog was further reacted with a 1,...
The reaction of a sulfur ylide with a chiral non-racemic sulfinyl imine afforded the desired aziridine in excellent yield and subsequent oxidation of the sulfinyl moiety dissolved in anhydrous dichloro-methane using a 75% aqueous solution of 3-chloro-per-oxy-benzoic acid afforded the title compound, C(14)H(27)NO(6)S. The configuration of the newly formed stereogenic center at the point of attac...
Surveys of cosmetic raw materials and finished products for the presence of the carcinogen 1,4-dioxane have been conducted by the U.S. Food and Drug Administration since 1979. Analytical methods are described for the determination of 1,4-dioxane in ethoxylated cosmetic raw materials and cosmetic finished products. 1,4-Dioxane was isolated by azeotropic atmospheric distillation and determined by...
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