595-48-2Relevant academic research and scientific papers
Miniolins A-C, novel isomeric furanones induced by epigenetic manipulation of Penicillium minioluteum
Tang, Hao-Yu,Zhang, Qiang,Gao, Yu-Qi,Zhang, An-Ling,Gao, Jin-Ming
, p. 2185 - 2190 (2015/02/05)
Cultivation of Penicillium minioluteum with azacitidine, a DNA methyltransferase inhibitor, led to the isolation of a novel type of aspertetronin dimer, named miniolins A-C (1-3), along with their precursor aspertetronin A (4). The structures of 1-3 were elucidated by extensive spectroscopic methods, and the absolute configurations were assigned by the chiral HPLC analysis of chemical degradation products and electronic circular dichroism associated with the TDDFT computational method (CAM-B3LYP/TZVP). The miniolins showed moderate cytotoxic activity against Hela cell lines. This journal is
Oxidation of methylmalonic acid by cerium(IV). Evidence for parallel reaction pathways
Kvernberg, Per Olav,Hansen, Eddy W.,Pedersen, Bjorn,Rasmussen, Asbjorn,Ruoff, Peter
, p. 2327 - 2331 (2007/10/03)
The reaction between methylmalonic acid (MeMA) and Ce(IV) ion in 1 M sulfuric acid/D2SO4 has been studied by means of 1H- and 13C-NMR. When MeMA is in excess, acetic acid, hydroxymethylmalonic acid, and pyruvic acid are formed as stable end products. When Ce(IV) is in stoichiometric excess, acetic acid is the only product. Approximately 70-80% of the MeMA forms rapidly acetic acid with hydroxymethylmalonic acid and pyruvic acid as reactive intermediates. The remaining MeMA reacts along parallel pathways and forms two intermediates, which slowly convert to hydroxymethylmalonic acid and pyruvic acid, respectively.
A new, facile synthesis of methyltartronic acid
An,D'Aloisio,Venturello
, p. 273 - 275 (2007/10/02)
A simple two-step approach to methyltartronic acid (2-hydroxy-2-methylpropanedioic acid, 3) from methacrylic acid (1) via α-methylglyceric acid (2) is described. It is based on the successive use of hydrogen peroxide and oxygen as oxidants in the same aqueous medium, in combination with tungstic acid and palladium on carbon as catalysts, respectively.
Process for preparing alkyl esters of methyltartronic acid
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, (2008/06/13)
There is described a process for preparing alkyl esters of methyltartronic acid by hydroxylation of methacrylic acid to alpha-methylglyceric acid with H2 O2, in an aqueous medium, in the presence of H2 WO4 and optionally of H3 PO4 or H3 AsO4 or alkaline salts thereof as catalysts, at pH3 in excess or with O2, in an aqueous-alkaline medium, in the presence of Pd or Pt carried on carbon or oxides thereof as catalysts, at temperatures of 60°-100° C., and final esterification of methyltartronic acid with alcohols C1 -C4.
Nucleophilic 1,2-Schifts of Alkoxycarbonyl and Carboxylate Groups in the Benzilic-Acid Type Rearrangement of α,β-Dioxobutiric Esters
Gowal, Heike,Dao, Le H.,Dahn, Hans
, p. 173 - 180 (2007/10/02)
tert-Butyl α,β-dioxobutyrate (hydrate; 1d) undergoes, at medium or high pH, the benzylic acid rearrangement with exclusive 1,2-shift of the COO(t-Bu) group; the same is the true for the corresponding isopropyl ester 1c and ethyl ester 1b at high pH, whereas the overall picture of these reactions is complicated by concurrent hydrolysis of the ester, followed by a 1,2-shift of the COO1- group.Consequently, the shift of these electron-attracting groups cannot be considered to be systematically disfavoured (compared, e.g., with alkyl-group shifts).Kinetic measurements of the rearrangement show for both esters (as well as for the analogous ethyl ester 1b, and also for ethyl 3-cyclopropyl-α,β-dioxopropionate (4)) a characteristic rate profile: at relatively low pH, k is proportional to 1->, approaching saturation with increasing 1-> (interpreted as complete transformation of the substrate into the hydrate monoanion), which is followed at higher pH by another rate increase with k proportional to 1-> (probably due to the reaction of the hydrate dianion).The similarity of k values for 1b-d shows that in the shift of COOR steric hindrance caused by R is negligible.
Oxidation of Creosol with Oxygen in Alkaline Aqueous Solution. Model Experiments on Oxygen Pulping of Wood
Fricko, Paul,Holocher-Ertl, Martin,Kratzl, Karl
, p. 1025 - 1042 (2007/10/02)
Reaction of creosol (2-methoxy-4-methyl-phenol) with oxygen in alkaline aqueous solution gave several neutral and acidic compounds which were identified.By quantitative determination of the degradation products an evaluation of the degradation pathways was possible. - Keywords: Cyclohexadienons as intermediates; Oxygen bleaching; Oxygen pulping; Phenol oxidation; Gas chromatography of methyl esters
