نتایج جستجو برای: dimethyl ether synthesis

تعداد نتایج: 450136  

Journal: :Organic letters 2005
Ji Duck Kim In Su Kim Cheng Hua Jin Ok Pyo Zee Young Hoon Jung

The total synthesis of (-)-cytoxazone 1 was achieved in six linear steps (34% overall yield) from p-anisaldehyde. The key steps in this route are the regioselective and stereoselective introduction of a N-protected amine group, using the CSI reaction of the anti-1,2-dimethyl ether 3, and the subsequent regioselective cyclization of the N-protected amino diol 13 to give the 2-oxazolidinone unit ...

2006
Dieter Enders

The asymmetric synthesis of the new lignan cubebin dimethyl ether was accomplished in eight steps with an overall yield of 40 %. In addition, the known lignans (+)-hinokinin and (+)-dihydrocubebin were synthesized by this route. Our approach involves the highly diastereoselective and enantioselective (de ≥ 98%, ee ≥ 98%) construction of a trans-substituted 2,3dibenzylbutyrolactone through an as...

Journal: :Applied and environmental microbiology 1994
M R Hyman C L Page D J Arp

Methyl fluoride and dimethyl ether were previously identified as inhibitors of ammonia oxidation and N2O production in autotrophic nitrifying bacteria. We demonstrate that methyl fluoride and dimethyl ether are substrates for ammonia monooxygenase and are converted to formaldehyde and a mixture of methanol and formaldehyde, respectively.

Journal: :The Journal of antibiotics 1980
W A König R Krause W Loeffler D Schanz

Ethericin B(Ia) was isolated together with ethericin A1) from fermentations of Aspergillus funiculosus Tü 680. The structure of ethericin B was established as 4-carbethoxy-5,5'-dihydro-xy-3,3'-dimethyl-diphenyl ether by chemical degradation, mass spectrometry, 1H-NMR and comparison with synthetic 4-carbethoxy-5,5'-dimethoxy-3,3'-dimethyl-diphenyl ether.

2013
F. J. Arriaga-Giner J. Rullkötter T. M. Peakman E. Wollenweber

The farinose coating on the lower frond surface of the fern Notholaena rigida Dav. was shown pre­ viously to contain the flavones scutellarein-6,7,4'trimethyl ether and scutellarein-6 ,7-dimethyl ether as well as minor amounts of apigenin, apigenin-4'methyl ether, and apigenin-7,4'-dimethyl ether [1], The exudate material also contains a considerable amount of terpenoids, one of which has been ...

Journal: :Organic letters 2006
Pin-Nan Cheng Chi-Feng Lin Yi-Huang Liu Chien-Chen Lai Shie-Ming Peng Sheng-Hsien Chiu

[structure: see text]. The crown ether BPX26C6 forms a [3]pseudorotaxane-like complex with the N,N'-dimethyl-4,4'-bipyridinium dication both in solution and in the solid state. The facile one-pot synthesis of a [2]rotaxane from neutral precursors-BPX26C6, 4,4'-dipyridyl, and 3,5-di-tert-butylbenzyl bromide-suggests that BPX26C6 may bind to (mono)pyridinium cations in a [2]pseudorotaxane-like ma...

2012
Zhen Chen Haitao Zhang Weiyong Ying Dingye Fang

Based on a global kinetics of direct dimethyl ether (DME) synthesis process from syngas, a steady-state one-dimensional mathematical model for the bubble column slurry reactor (BCSR) has been established. It was built on the assumption of plug flow of gas phase, sedimentation-dispersion model of catalyst grains and isothermal chamber regardless of reaction heats and rates for the design of an i...

Journal: :Applied and environmental microbiology 1993
G V Wolfe R P Kiene

We examined the effects of a variety of amendments on the consumption of [U-C]dimethyl sulfide in a Georgia salt marsh. Methylated compounds, particularly those with dimethyl groups, significantly inhibited dimethyl sulfide consumption, while nonmethylated substrates had little effect. Dimethyl disulfide and dimethyl ether were the most effective inhibitors tested.

Journal: :Environmental Health Perspectives 1995
M Fisher

Kathryn Rosica of the Chemical Manufacturers Association raised an interesting point in her letter (EHP vol. 102, p. 1006). Neither the term "glycol ethers" nor the term "ethylene glycol ethers" strictly identifies a class of chemicals whose members all share a common distinctive toxicological profile. As Rosica correctly noted, "Higher molecular weight ethylene glycol monoethers that have been...

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