- Base- A nd Catalyst-Induced Orthogonal Site Selectivities in Acylation of Amphiphilic Diols
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Seeking to selectively functionalize natural and synthetic amphiphiles, we explored acylation of model amphiphilic diols. The use of a nucleophilic catalyst enabled a remarkable shift of the site selectivity from the polar site, preferred in background noncatalyzed or base-promoted reactions, to the apolar site. This tendency was significantly enhanced for organocatalysts comprising an imidazole active site surrounded by long/branched tails. An explanation of these orthogonal modes of selectivity is supported by competitive experiments with monoalcohol substrates.
- Ashush, Natali,Dobrovetsky, Roman,Fallek, Amit,Fallek, Reut,Portnoy, Moshe
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- Preparation method of halogenated acid compounds
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The present invention discloses a method for preparing halogenated acid compounds. Specifically, the present invention provides a method for preparing halogenated acid compounds as shown in formula I, which takes the halogen alcohol compounds shown in formula II as raw materials, reacts with TEMPO, sodium hypochlorite and sodium chlorite, adjusts the reaction pH with inexpensive carbon dioxide, and finally prepares halogenated acid compounds. The preparation method has high yield, relatively little toxicity and environmental protection, which is suitable for industrial production.
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Paragraph 0078-0093
(2022/03/31)
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- Synthesis method of ethyl 8-bromocaprylate
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The invention provides a synthesis method of ethyl 8-bromocaprylate, which comprises the following steps: S1, carrying out substitution reaction on 1,6-dibromohexane and diethyl malonate to obtain a compound 2-(6-bromohexyl)-diethyl malonate; S2, enabling the 2-(6-bromohexyl)-diethyl malonate to carry out ester hydrolysis and a decarboxylation reaction so as to obtain 8-bromocaprylic acid; and S3, carrying out an esterification reaction on the 8-bromocaprylic acid and absolute ethyl alcohol to obtain ethyl 8-bromocaprylate. According to the synthesis method of ethyl 8-bromocaprylate, disclosed by the embodiment of the invention, firstly, 1,6-dibromohexane initial raw material and diethyl malonate are subjected to substitution reaction to generate 2-(6-bromohexyl) diethyl malonate, and then ester hydrolysis and decarboxylation reaction are carried out to obtain 8-bromocaprylic acid; and finally,esterification reaction is carried out to generate ethyl 8-bromocaprylate. The raw materials are easy to obtain, side reactions in the reaction are few, the process is simple, and the method is suitable for industrial production, and has a very wide application prospect.
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- Design, synthesis, and biological evaluation of potent photoaffinity probes of oleanolic acid
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To study the target proteins of oleanolic acid, a series of novel photoaffinity probes were designed and synthesized. Their affinity for the target proteins was evaluated in an enzyme inhibition assay against glycogen phosphorylase, a known target protein of oleanolic acid. Among these compounds, probe 2 exhibited the most potent activity with an IC50value of 5.98 μM, which was about 2.5-fold more potent than its parent compound oleanolic acid. The results showed that the synthesized photoaffinity probes retained the binding affinity for their target proteins, and might be used as powerful tools to fish out the target proteins of oleanolic acid.
- Zhang, Liying,Dong, Jizhe,Zhang, Yingxia,Liu, Jun,Zhang, Luyong,Sun, Hongbin
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p. 294 - 302
(2013/07/28)
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- Carbon-carbon bond fission on oxidation of primary alcohols to carboxylic acids
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α-Carbon-carbon bond cleavage is shown to be a general side reaction accompanying the oxidation of unbranched primary alcohols to the corresponding carboxylic acids using HNO3, CrO3/H2SO 4/H2O/acetone, CrO3/CH3COOH, PDC/DMF, H5IO6/CrO3, KMnO4/H +, KMnO4/HO-, NiCl2/NaClO, TEMPO/PhI(OAc)2. Therefore, the product formed is always contaminated with a carboxylic acid containing one carbon atom less. Systems such as PhI(OAc)2/TEMPO or H5IO6/CrO 3/CH3CN reduce to a minimum the content of this impurity. Temperature, the order of reagent addition, and additives such as oxalic acid or cerium salts produce a profound effect on the formation of the undesirable impurity during the Jones oxidation of primary alcohols.
- Bekish, Andrei V.
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scheme or table
p. 3082 - 3085
(2012/07/28)
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- Synthesis, antiproliferation, and docking studies of N-phenyl-lipoamide and 8-mercapto-N-phenyloctanamide derivatives: Effects of C6 position thiol moiety
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Some N-phenyl lipoamide and 8-mercapto- N-phenyloctanamide derivatives were synthesized and their in vitro antiproliferative activity was evaluated. The experimental results indicated that 8-mercapto-N-phenyloctanamides might be good histone deacetylase inhibitors rather than N-phenyl lipoamides, who had thiol moiety at C6 position. To verify the antiproliferation data on structural basis, in silico docking studies of the representative compounds into the crystal structure of histone deacetylase- like protein using AutoDock 4.0 program were performed. Furthermore, sulfur acetylated 8-mercapto-Nphenyloctanamide improved its in vitro antiproliferative activity, probably due to the increasing of its cell membrane permeability. While the identification of enzymatic target of N-phenyl lipoamides with dithiolane is still ongoing. Springer Science+Business Media, LLC 2011.
- Zhang, Shi-Jie,Hu, Wei-Xiao
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p. 3312 - 3320
(2012/11/07)
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- A simple and cost effective synthesis of 3,11-dimethylnonacosan-2-one, a female sex pheromone of the German cockroach
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A convenient synthesis of 3,11-dimethylnonacosan-2-one (1) is described. Our strategy involves the use of well known C-alkylation and ethyl acetoacetate synthesis reactions as key steps. We expect that this method will prove to be useful for large scale preparation of 1 and modification of dimethylnonacosanones.
- Ahn, Kwang-Chan,Jung, Jae-Chul,Park, Oee-Sook
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p. 751 - 757
(2007/10/03)
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- Influence of terminal branching on the transdermal permeation-enhancing activity in fatty alcohols and acids
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In order to investigate the effect of terminal chain branching in the skin permeation enhancers, seven alcohols and seven acids with the chain length of 8-12 carbons and terminal methyl or ethyl branching were prepared. Their transdermal permeation-enhancing activities were evaluated in vitro using theophylline as a model permeant and porcine skin, and compared to those of the linear standards. Terminal methyl branching increased the enhancing activity only in 12C acid, no effect was seen in the shorter ones. Terminal ethyl however produced a significant increase in activity. In the alcohols, the branching was likely to change the mode of action, due to a different relationship between the activity and the chain length.
- Klimentova, Jana,Kosak, Petr,Vavrova, Katerina,Holas, Tomas,Hrabalek, Alexandr
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p. 7681 - 7687
(2007/10/03)
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- Process for the monoalkylation of C-H acid methylene groups
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The ratio of the alkali(ne earth) carbonate to the methylene group-containing substrate is above 0.6 : 1 in the monoalkylation of C-H acid methylene groups by reaction of the substrate in a polar aprotic solvent with a dihalogen compound having its halogens separated by a chain of at least3C and with reaction being in presence of the alkali(ne earth) carbonates and a phase transfer catalyst and being accompanied by continuous removal of the water formed. An Independent claim is also included for production of omega-haloalkyl-nitriles or -carboxylic acids by reacting a malonic acid diester or cyanoacetic ester with an alpha,omega-dihaloalkane as above and then saponifying and decarboxylating the product.
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Page/Page column 6
(2008/06/13)
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- Asymmetric synthesis of unnatural (Z,Z,E)-octadecatrienoid and eicosatrienoid by lipoxygenase-catalyzed oxygenation
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The asymmetric synthesis of unnatural 13-hydroxy-(6Z,9Z,11E,13S)-octadecatrienoid and 15-hydroxy-(8Z,11Z,13E,15S)-eicosatrienoid is described using a biomimetic oxidation route. The main highlights of this synthesis are the asymmetric hydroxylation of the substrate with soybean lipoxygenase and cis selective Wittig olefination.
- Nanda,Yadav
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p. 1799 - 1806
(2007/10/03)
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- A simple and highly efficient deprotecting method for methoxymethyl and methoxyethoxymethyl ethers and methoxyethoxymethyl esters
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A series of methoxyethoxymethyl (MEM)- and methoxymethyl (MOM)-ethers and MEM-esters were hydrolyzed to their corresponding alcohols and carboxylic acids by a catalytic amount of CBr4 (10%) in iPrOH under refluxing reaction condition. The chemoselective hydrolysis between R3Si- and MEM-protected alcohols can be achieved by using different steric bulkness solvents such as MeOH or iPrOH.
- Shih-Yuan Lee, Adam,Hu, Yi-Jung,Chu, Shu-Fang
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p. 2121 - 2126
(2007/10/03)
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- Benzimidazole compounds containing 1,2,4-triazole ring, and compositions and methods of use containing the same
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Benzimidazole compounds represented by the formula set out below and analogs thereof, wherein Y represents a single bond or sulfur atom; Z represents oxygen atom, sulfur atom, or N--R4 ; R1 and R2 independently represent hydrogen, a halogen atom, alkyl group or other; R1 and R4 independently represent hydrogen, alkyl group, acyl group or other; n and m independently represent an integer of 1, 2, or 3; and L represents a linking group such as C2-12 alkylene group or an alkylene group containing one or more phenylene groups or ether groups. The compounds are useful as an active ingredient of a medicament such as a preventive and therapeutic medicament for hyperlipemia or arterial sclerosis. STR1
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- Restricting the flexibility of crosslinked, interfacial peptide inhibitors of HIV-1 protease
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Interfacial peptides of HIV-1 protease were crosslinked with varying length alkyl-chains containing either a single cis or trans double bond, or a triple bond to remove degrees of freedom within the tethers. The synthesis of these compounds and their effects on the activity of HIV-1 protease are described.
- Ulysse, Luckner G.,Chmielewski, Jean
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p. 3281 - 3286
(2007/10/03)
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- Useful Direct Conversion of Tetrahydropyranyl Ethers of Fatty Alcohols into Fatty Acids
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Tetrahydro-2-pyranyl ethers from fatty primary alcohols can be converted in a one-step procedure into the corresponding carboxylic acids in high yields.This process avoids the synthesis of symmetrical esters, particularly for long-chain compounds.This reaction proved to be useful, for instance, to produce polyunsaturated fatty acids immediately before their biological testing. - Key words: Oxidation; polyunsaturated fatty acids; tetrahydropyranyl ethers
- Gruiec, Regine,Noiret, Nicolas,Patin, Henri
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p. 1083 - 1085
(2007/10/03)
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- Synthesis of Very Long Fatty Acid Methyl Esters
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Phosphoranes, produced by treating alkyltriphenylphosphonium bromides with lithium hexamethyldisilazide, reacted with ω-oxo esters to give modest yields of the corresponding methyl cis-alkenoates.By an alternative method, treatment of ω-iodo esters with the complexes formed from reactions of alkylcopper(I) and Grignard reagents gave methyl alkanoates, cis-alkenoates, and methylene-interrupted cis,cis-alka-dienoates and cis,cis,cis-trienoates.The stereochemical integrity of the esters was determined by 13C NMR spectroscopy.
- Kling, Marcel R.,Easton, Christopher J.,Poulos, Alf
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p. 1183 - 1190
(2007/10/02)
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- A GENERAL METHOD FOR THE SYNTHESIS OF DIACETYLENIC ACIDS
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A simple and convenient method for the synthesis of twelve novel alkadiynoic acids, HOOC(CH2)mCC-C-CC(CH2)n-CH3, is reported.
- Singh, Alok,Schnur, Joel M.
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p. 847 - 852
(2007/10/02)
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- Short and Efficient Syntheses of Coriolic Acid
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Coriolic acid (1), a divalent cation ionophore and a self-defensive substance against blast disease in rice plant, has been synthesized by two convenient approaches.
- Rao, A. V. Rama,Reddy, S. Pulla,Reddy, E. Rajarathnam
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p. 4158 - 4159
(2007/10/02)
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- Processes for producing 7-octen-1-al and derivatives thereof
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There are disclosed a process for producing 7-octen-1-al which comprises isomerizing 2,7-octadien-1-ol in the presence of a catalyst comprising oxides of at least two metals selected from the group consisting of copper, chromium and zinc and processes for producing derivatives of 7-octen-1-al.
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- Acides gras marques en position ω par un nucleide radioactif emetteur γ
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The synthesis of many saturated, acetylenic, olefinic (Z or E) fatty acids labeled with 123I or 131I at the ω-position has been achieved.The radioactive iodine atom is introduced by a I-, *I- exchange reaction; the influence on the yield of several parameters - presence of iodine carrier, fatty acid and water concentrations, solution acidity - has been studied.Experimental conditions which produce labeling yields higher than 95percent have been defined; these results have lead to a very easy labeling method used in several hospitals in the external study of myocardial metabolism of fatty acids.
- Riche, Francoise,Mathieu, Jean-Paul,Vincens, Maurice,Bardy, Andre,Comet, Michel,Vidal, Michel
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