نتایج جستجو برای: βunsaturated ketones moieties

تعداد نتایج: 19705  

2016
Vittal Shivva Ian G. Tucker Stephen B. Duffull

Gastrointestinal absorption and disposition of ketones is complex. Recent work describing the pharmacokinetics (PK) of d-β-hydroxybutyrate (BHB) following oral ingestion of a ketone monoester ((R)-3-hydroxybutyl (R)-3-hydroxybutyrate) found multiple input sites, nonlinear disposition and feedback on endogenous production. In the current work, a human systems pharmacology model for gastrointesti...

Journal: :Organic & biomolecular chemistry 2015
Wei Wu Xuxue Zhang Fang Liang Song Cao

A straightforward and convenient approach for trifluoromethylthiolation of various acyclic and cyclic ketones with PhNHSCF3 is described. The reaction proceeds smoothly in the presence of acetyl chloride at room temperature and affords α-trifluoromethylthiolated ketones in fair to good yields.

2011
Hayden White Balasubramanian Venkatesh

Although much feared by clinicians, the ability to produce ketones has allowed humans to withstand prolonged periods of starvation. At such times, ketones can supply up to 50% of basal energy requirements. More interesting, however, is the fact that ketones can provide as much as 70% of the brain's energy needs, more efficiently than glucose. Studies suggest that during times of acute brain inj...

2005
J. R. KIRSCH

When exposed to hypoxia, intact mice, with elevated blood ketones, live longer than mice with normal blood ketones. To evaluate a possible mechanism responsible for this phenomenon a rat brain slice preparation was used to determine if brain tissue would utilize glucose or ketones preferentially during exposure to reduced oxygen. Reducing available oxygen in the incubation medium from 95%, in s...

Journal: :Journal of the American Chemical Society 2005
Nidhi Singhal Apurba L Koner Prasenjit Mal Paloth Venugopalan Werner M Nau Jarugu Narasimha Moorthy

The diastereomers of ketones 2 and 3 are shown to exhibit distinct photochemical reactivities due to conformational preferences; while the anti isomers of 2 and 3 undergo efficient Yang cyclization in 75-90% yields with a remarkable diastereoselectivity (> 90%), the syn isomers predominantly undergo Norrish Type II elimination. The differences in the product profiles of the diastereomers are co...

Journal: :Chemical communications 2012
Takahiro Nishimura Akira Noishiki Tamio Hayashi

Asymmetric addition of arylboroxines to δ-aryl-α,β,γ,δ-unsaturated ketones proceeded in the presence of an iridium catalyst coordinated with a chiral diene ligand to give high yields of δ-diaryl ketones with very high enantioselectivity.

Journal: :Organic & biomolecular chemistry 2015
Lulu Fan Shinobu Takizawa Yoshiki Takeuchi Kazuhiro Takenaka Hiroaki Sasai

Catalytic synthesis of chiral spirocyclic ketones was accomplished via the Pd-catalyzed intramolecular α-arylation of α-substituted cyclic ketones. The obtained spirocyclic ketone could be converted into a bifunctional organocatalyst.

Journal: :Chemical communications 2011
Andre Jakoblinnert Radoslav Mladenov Albert Paul Fabrizio Sibilla Ulrich Schwaneberg Marion B Ansorge-Schumacher Pablo Domínguez de María

The asymmetric reduction of ketones is performed by using lyophilized whole cells in neat substrates with defined water activity (a(w)). Ketones and alcohols prone to be unstable in aqueous media can now be converted via biocatalysis.

Journal: :European Journal of Organic Chemistry 2021

A Wittig reaction of 3-hydroxyphtalide (11) gave ortho-sty­rene-2-carboxylic acid (12). Its Weinreb amide 13 acylated heterosub­stituted methyllithiums. This led to aryl “methyl” ketones whose sp3-carbon was substituted by Cl + OMe (in 14a), 2 ´ 14b), OtBu 17a), SPh 17b) or SO2Ph 17c). The enolates these were C-allylated. furnished the benzene-fused octa-1,8-dienones 7a-b and 9a-c, respectively...

Journal: :Journal of the American Chemical Society 2011
Jason R Cox Peter Müller Timothy M Swager

We detail our efforts toward the selective detection of cyclic ketones, e.g. cyclohexanone, a component of plasticized explosives. Thin films comprised of a conjugated polymer are used to amplify the emission of an emissive receptor via energy transfer. We propose that the energy transfer is dominated by an electron-exchange mechanism to an upper excited state of the fluorophore followed by rel...

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