M-Hydroxycarboxylic

An example of an exo-trig process would be lactonization of a m-hydroxycarboxylic acid ... 

Cleansing compounds -glycobic acid m [HYDROXYCARBOXYLIC ACIDS] (Vol 13)... 

Diphenylphosphinyl chloride N-methylmorpholineltriethylamine Phenol ring from 3,5-dienecarboxylic acids m-Hydroxycarboxylic acid esters... 

Fundamental progress in this field was achieved by the group of Park et al. [28]. In their elegant study, a biocatalytic process was designed and investigated for the production of long-chain a,co-dicarboxylic acids (e.g., CIO) and m-hydroxycarboxylic acids (e.g., C9, Cll, C13) from renewable fatty acids ofplant and animal origin (e.g., oleic acid, ricinoleic acid) which represent important renewable feedstock resources... 

When applied to 5- or 6-hydroxycarboxylic acids, this reaction gives cycliza tion products m good yield [99] (equations 50 and 51)... 

Dochnahl M, Fu GC (2009) Catalytic asymmetric cycloaddition of ketenes and nitroso compounds enantioselective synthesis of a-hydroxycarboxylic acid derivatives. Angew Chem Int Ed 48 2391-2393... 

Acidification with trichloracetic acid catalyses oxidation , the fractional increase in the rate coefficient per mole of acid added, viz. Ak/ko)/[sicid], being of the order of two. Strong catalysis by alkali metal acetates has been observed for several oxidations, e.g. of m-cyclohexane-l,2-diol °, formic acid , methyl mannoside and galactoside and several a-hydroxycarboxylic acids °. 

Cornell, R.M. Schindler, P.W. (1980) Infrared study of the adsorption of hydroxycarboxylic adds on a-FeOOH and amorphous Fe (III)-hydroxide. Colloid Polymer Sd. 258 1171-1175... 

Oxidation of cyclic ketones by H2O2 in the presence of an acid zeolite was used for the preparation of lactones and u-hydroxycarboxylic acids [124]. Thus, for c-pentanone oxidation in the presence of H-ZSM-5, -valerolactone is obtained with 62.3% selectivity at 40% conversion, whereas 5-hydroxy-pentoic acid is obtained with 34% yield in the presence of Zeolon M. 

Although the pictorial comparison shown in Fig. 1.1 and discussed above is true at low and average cement contents up to about 350 kg m it is more difficult to obtain higher strengths and workability by further increasing the cement content. It is in this area that the hydroxycarboxylic acid water-... 

Datta, R. (1995) Hydroxycarboxylic acids. In Kroschwitz, J.I. Howe-Grant, M., eds, Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed., Vol. 13, New York, John Wiley, pp.1042-1062... 

Formation constants for the species [M(OAc) ]<2-")+ (M = Zn or Cd n = 1-3) have been determined in addition, zinc forms a tetraacetato complex.692,693 Stability constants for complexation of Zn2+ and Cd2+ by other carboxylic694,695 and hydroxycarboxylic adds696 699 have been reported. 

Emulsifying agents - [ALKANOLAMINES - ALKANOLAMINESFROMNITRO ALCOHOLS] (Vol2) -esters of lactate salts [HYDROXYCARBOXYLIC ACIDS] (Vol 13) -m floor polishes [POLISITES] (Vol 19)... 

Portanova, R. Lajunen, L.H.J. Tolazzi, M. Piispanen, J. Critical evaluation of stability constants for alpha-hydroxycarboxylic acid complexes with protons and metal ions and the accompanying enthalpy changes. Part II. Aliphatic 2-hydroxycarboxylic acids. Pure Appl. Chem. 2003, 75 (4), 495-540. 

Toda, F., Sano, A., Nassimbeni, L. R., and Niven, M. L. (1991) Optical Resolution of Amino Acid and Hydroxycarboxylic Acid Esters by Complexation with Optically Active Host Compounds a Crystallographic Result, J. Chem. Soc., Perkin Trans. 2, 1971-1975. 

M Arthur, C Molinas, S Dutka-Malen, P Courvalin. Structural relationship between the vancomycin resistance protein VanH and 2-hydroxycarboxylic acid dehydrogenases. Gene 103(1) 133—134, 1991. 

Biagioli, M., L. Strinna-Erre, G. Micera, A. Panzanelli, and M. Zema. 2000. Molecular structure, characterization and reactivity of dioxo complexes formed by vana-dium(V) with a-hydroxycarboxylate ligands. Inorg. Chim. Acta 310 1-9. 

Reufer Ch., Hateley, M., Lehmann, Th., Weckbecker, Ch., Sanzenbacher R. and Bilz, J. (2006) Process for the preparation of a-substituted carboxylic acids from the series comprising a-hydroxycarboxylic acids and N-substituted a-aminocarboxylic acids. European patent EP... 

Hydroxycarboxylate compounds of Mn111 are known for salicylates and various aliphatic acids.299 Some crystalline solids have been isolated, including bis-chelate species of the salicylates M[Mn(X-sal)2L2] (L = H20, py) but the only tris-chelate compound isolated is the black Cs3[Mn (CF2)2C(0)COO 3]. Various red or green crystalline solids also are known with tartrate ligands and they are reasonably robust, but no structural data are available. 

Analogously, Van Pelt et al. (2009) have realized a one-pot bienzymatic cascade combining the (5 )-selective oxynitrilase from M. esculenta and a purified nitrile hydratase from Nitriliruptor alkaliphilus for the synthesis of aliphatic S)-a-hydroxycarboxylic amides (Table 17.6) both enzymes were immobilized as CLEAs to enhance their stability (Van Pelt et al., 2009). 

I 76 Nitrilases m the Enantio%etective Synthesis of a-Hydroxycarboxylic Acids... 

Cartoni et al. [88] studied perspective of the use as stationary phases of n-nonyl- -diketonates of metals such as beryllium (m.p. 53°C), aluminium (m.p. 40°C), nickel (m.p. 48°C) and zinc (liquid at room temperature). These stationary phases show selective retention of alcohols. The retention increases from tertiary to primary alcohols. Alcohols are retained strongly on the beryllium and zinc chelates, but the greatest retention occurs on the nickel chelate. The high retention is due to the fact that the alcohols produce complexes with jS-diketonates of the above metals. Similar results were obtained with the use of di-2-ethylhexyl phosphates with zirconium, cobalt and thorium as stationary phases [89]. 6i et al. [153] used optically active copper(II) complexes as stationary phases for the separation of a-hydroxycarboxylic acid ester enantiomers. Schurig and Weber [158] used manganese(ll)—bis (3-heptafiuorobutyryl-li -camphorate) as a selective stationary phase for the resolution of racemic cycUc ethers by complexation GC. Picker and Sievers [157] proposed lanthanide metal chelates as selective complexing sorbents for GC. Suspensions of complexes in the liquid phase can also be used as stationary phases. Pecsok and Vary [90], for example, showed that suspensions of metal phthalocyanines (e.g., of iron) in a silicone fluid are able to react with volatile ligands. They were used for the separation of hexane-cyclohexane-pentanone and pentane-water-methanol mixtures. 

HYDROXY-3-ALKYLCYCLOPENT-2-ENE-1-ONES Sulfuric acid. a-HYDROXY CARBONYL COMPOUNDS m-Chloroperbenzoic acid. a-HYDROXYCARBOXYLIC ACIDS f-Butyldimethylsilyl cyanide. 

The hydroxycarboxylates are known in a range of crystalline binary Mn hydrates,but the only ternary compounds are a SNOj-salicylate, which is probably Na2[MnL2(H20)2], and the Na and K tartrates M,MnC4H20eBoth the aliphatic and aromatic (only salicylates) hydroxycarboxylates form 1 1 and 1 2 species in aqueous solution, which are of relatively low stability, and much of the interest to date has been in their oxidations to Mn " and Mn —such oxidations being readily achieved in alkaline solutions, especially as the number of hydroxy groups on the ligand is increased. 

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