ChemInform Abstract: A Route to Homochiral (S)-O-Methyl Mandelic Acid and Related α- Alkoxy Carboxylic Acids from Isopropylidene Glycerol.

ChemInform ◽  
2010 ◽  
Vol 26 (47) ◽  
pp. no-no
Author(s):  
S. HANDA ◽  
J. E. HAWES ◽  
R. J. PRYCE
Keyword(s):  
Carboxylic Acids ◽  
Mandelic Acid ◽  
Isopropylidene Glycerol

scholarly journals Enantioselective Protonation of Radical Anion Intermediates in Photoallylation and Photoreduction Reactions of 3,3-Diaryl-1,1-dicyano-2-methylprop-1-ene with Allyltrimethylsilane

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2677
Author(s):  
Hajime Maeda ◽  
Masayuki Iida ◽  
Daisuke Ogawa ◽  
Kazuhiko Mizuno
Keyword(s):  
Electron Transfer ◽  
Acetic Acid ◽  
Proton Transfer ◽  
Carboxylic Acids ◽  
Photoinduced Electron Transfer ◽  
Radical Anion ◽  
Mandelic Acid ◽  
Proton Source ◽  
Acetonitrile Solutions ◽  
Electron Transfer Pathways

Photoreactions of acetonitrile solutions of 3,3-diaryl-1,1-dicyano-2-methylprop-1-enes (1a–c) with allyltrimethylsilane (2) in the presence of phenanthrene as a photoredox catalyst and acetic acid as a proton source formed photoallylation (3) and photoreduction (4) products via photoinduced electron transfer pathways. When (S)-mandelic acid was used as the proton source, the reactions proceeded with 3.4 and 4.8 %ee for formation of 3 and 4, respectively. The results of studies of the effect of aryl ring substituents and several chiral carboxylic acids suggested that the enantioselectivities of the reactions are governed by steric controlled proton transfer in intermediate complexes formed by π-π and OH-π interactions of anion radicals derived from 1a–c and chiral carboxylic acids.

scholarly journals HOMOGENEOUS VINYLATION OF 2-HYDROXY-2 PHENYLETHANICAL ACID

2018 ◽  
Vol 6 (11) ◽  
pp. 350-354
Author(s):  
Parmanov A.B. ◽  
Nurmanov S.E. ◽  
Tomash Maniecki ◽  
Ziyadullayev O.E. ◽  
Abdullayev J.U.
Keyword(s):  
Carboxylic Acids ◽  
Vinyl Ester ◽  
Mandelic Acid ◽  
Heterogeneous Catalysts ◽  
Raw Materials ◽  
Zinc Salt ◽  
Vinyl Esters ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Ethylene Series

Homogeneous-catalytical vinylation of 2-hydroxy-2-phenylethanical acid was carried out. Influence of catalylists nature, temperature and duration reaction on yield of synthesized vinyl ester has been investigated. basis of natural raw materials. Based on vinyl esters of carboxylic acids, their polymers and copolymers with unsaturated compounds of the ethylene series, emulsifiers for emulsion paints have been obtained; compounds that improve the viscosity of lubricating oils and are used as crosslinking agents in the rubber industry. Synthesis of vinyl esters based on monobasic aliphatic acids has been studied by the example of acetic acid by many researchers. In this respect, the aromatic carboxylic acids remain unexplored. Goal: Synthesis of vinyl ester of mandelic acid by it’s reaction with acetylene in the presence of heterogeneous catalysts, investigation of the influence of the nature of catalysts and the reaction temperature on the yield of obtained product. Methodology: Catalytic systems based on AlCl3∙6H2O or zinc salt of mandelic acid with dimethylsulfoxide were prepared and heterogeneous catalytic vinylation of mandelic acid with acetylene was carried out and it’s vinyl ether was obtained. Scientific Novelty. The synthesis of vinyl ester of mandelic acid with it’s reactions with acetylene using the catalytic systems AlCl3∙6H2O-DMSO and (C6H5CH(OH)COO)2Zn-DMSO was carried out. Obtained Data: The vinyl ester of mandelic acid was synthesized by it’s vinylation in stationary heterogeneous conditions. The influence of the nature of the catalyst (AlCl3∙6H2O, (C6H5CH(OH)COO)2Zn), temperature and duration of the reaction on the yield of the product was investigated. Features: vinylation of hydroxy carboxylic acid was investigated; the catalytic systems AlCl3∙6H2O-DMSO and (C6H5CH(OH)COO)2Zn-DMSO are used; factors influencing the yield of vinyl ester of mindalic acid and optimal conditions of it’s synthesis were found.

scholarly journals Factors affecting the synthesis of ampicillin and hydroxypenicillins by the cell-bound penicillin acylase of Escherichia coli

1969 ◽  
Vol 115 (4) ◽  
pp. 757-764 ◽  
Author(s):  
M. Cole
Keyword(s):  
Escherichia Coli ◽  
Carboxylic Acids ◽  
Mandelic Acid ◽  
Penicillin Acylase ◽  
Gram Negative Bacteria ◽  
Rapid Synthesis ◽  
Gram Negative ◽  
Factors Affecting ◽  
Optimum Ph ◽  
Derivatives Of

1. The effect of pH, temperature, reactant concentration and reaction time has been investigated for the synthesis of benzylpenicillin, dl-α-hydroxybenzylpenicillin and d-α-aminobenzylpenicillin from 6-aminopenicillanic acid by the penicillin acylase of Escherichia coli. 2. Synthesis of penicillins from carboxylic acids proceeds most rapidly at pH5; with amides the optimum pH is higher (6–7) but the reverse reaction rapidly sets in. This can be counteracted by lowering the pH or adding more amide. Optimum temperatures are 35–40°. 3. Most rapid synthesis of penicillin was obtained with the N-acylglycine and methyl ester derivatives of carboxylic acids. Increasing the amide/6-APA ratio above 1:1 raised the rate of synthesis of penicillins. 4. Preferential synthesis of d-α-hydroxybenzylpenicillin takes place in a reaction mixture containing dl-mandelic acid. 5. From d- and l-mandelamide, d- and l-α-hydroxybenzylpenicillins were prepared, the former being more bioactive than the latter. p-Hydroxy- and 3,4-dihydroxybenzylpenicillins were also prepared, the latter being more active against some Gram-negative bacteria than benzylpenicillin.

A convenient preparative method for 1,4-diketones from carboxylic acids

1977 ◽  
Vol 27 (1) ◽  
pp. 117-120
Author(s):  
Shoji Watanabe ◽  
Tsutomu Fujita ◽  
Kyoichi Suga ◽  
Haruhiko Abe
Keyword(s):  
Carboxylic Acids ◽  
Preparative Method
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