1518-62-3Relevant academic research and scientific papers
Mass spectrometric studies of trimethylsilylpantothenic acid and related substances
Rychlik, Michael
, p. 555 - 562 (2001)
The characteristic fragment of trimethylsilylated pantothenic acid (TMS-PA) at m/z 291 upon electron ionization was shown to originate from the molecular ion by a McLafferty rearrangement instead of by ejection of 1,1,3,3-tetramethyl-1,3-disilacyclobutane. The verification consisted of labelling experiments and high-resolution mass spectrometry of the fragment and studies on its isotopic distribution. The remaining fragmentation pathways of TMS-PA were clarified by B/E-linked scans and collision-induced dissociation. Copyright
The degradation of L-threose at Maillard reaction conditions
Li, Elaine Yinan,Feather, Milton S.
, p. 41 - 48 (1994)
L-Threose, a comparatively unstable aldose, is produced from L-ascorbic acid in the presence of oxygen and participates vigorously in Maillard reactions, even at comparatively mild conditions.In the present study, the degradation of L-threose at pH 7.0 alone, in the presence of N-α-acetyl-L-lysine, and at pH 2.0 alone at 37 deg C was investigated by identification of some of the products produced in the reactions by means of GLC and GLC-MS.Among the compounds identified were 3-deoxy-tetros-2-ulose (1), the predicted alkaline rearrangement product derived from 1 (2,4-dihydroxybutyrate, the 4-carbon metasaccharinic acid), as well as glyceraldehyde.Isotopic tracer studies clearly show that the glyceraldehyde is produced by loss of C-1 from the starting L-threose molecule.The presence of N-acetyl lysine in incubation solutions appears to accelerate the production of 1, but the formation of glyceraldehyde appears to be independent of the lysine derivative.
Process for treating homoserin compounds
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Paragraph 0286-0292, (2017/01/02)
The present invention relates to the preparation of a useful compound which can be used as an intermediate product for preparing an important compound in the industrial field from a homoserine-based compound and provides a process for treating a homoserine-based compound, capable of simply mass producing a useful compound from a homoserine-based compound with excellent efficiency.(AA) Homoserine-based compound(BB) Product(CC) GBL derivative(DD) Halo-GBL(EE, FF, GG) GBL puranone(HH) Puranone(II) Dialkyl succinate(JJ) Step 1(KK) Step 2(LL) Step 3(MM) Step 4(NN) Step 5(OO) Step 6(PP) Step 7COPYRIGHT KIPO 2016
METHOD FOR PREPARING 2-HYDROXYBUTYROLACTONE
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Paragraph 0125; 0126, (2013/08/15)
The invention relates to a method for preparing 2-hydroxybutyrolactone (2HBL) from a compound or its salt or its oligomers, said compound fitting formula (I) [in-line-formulae]CH3—S—CH2CH2CR1R2R3[/in-line-formulae]WhereinR1 represents HR2 represents a group selected from OH; OR4 and OCOR4 wherein R4 represents a group selected from linear, cyclic, alicyclic or branches alkyl groups having from 1 to 10 carbon atoms, and aryl groups having from 6 to 10 carbon atoms, optionally substituted with substituent(s) selected from linear or branched alkyl groups having from 1 to 10 carbon atoms, halogens and hydroxyl, amino, nitro and alkoxy groups having from 1 to 10 carbon atoms; and OSiRR′R″ wherein R, R′ and R″ are selected independently of each other from linear, cyclic, alicyclic or branched alkyl groups having from 1 to 10 carbon atoms, aryl groups having from 6 to 10 carbon atoms, optionally substituted with substituent(s) selected from linear or branched alkyl groups having from 1 to 10 carbon atoms, or R1 and R2 represent together ═O,R3 represents COOH or a COOR5 group wherein R5 represents a group selected from linear, cyclic, alicyclic or branched alkyl groups having from 1 to 10 carbon atoms, benzyl groups and benzyl groups substituted with one or two substituents selected from linear or branched alkyl groups having from 1 to 10 carbon atoms, halogens and hydroxyl, amino, nitro and alkoxy groups having from 1 to 10 carbon atoms, or R3 represents a cyano group,method according to whicha sulfonium of said compound is obtained, said sulfonium fitting the formula (II) [in-line-formulae][CH3][CH2CH2CR1R2CR3][CR6R7R8]S+X?[/in-line-formulae]wherein R1, R2 and R3 have the above definition, and R6 and R7 are selected independently of each other from H, linear, cyclic, alicyclic or branched alkyl groups having from 1 to 10 carbon atoms, and aryl groups having from 6 to 10 carbon atoms, optionally substituted with substituent(s) selected from linear or branched alkyl groups having from 1 to 10 carbon atoms, halides and hydroxyl, amino, nitro and alkoxy groups having from 1 to 10 carbon atoms; R8 is selected from H, linear, cyclic, alicyclic or branched alkyl groups having from 1 to 10 carbon atoms, aryl groups having from 6 to 10 carbon atoms, optionally substituted with substituent(s) selected from linear or branched alkyl groups having from 1 to 10 carbon atoms, and attractor groups notably those comprising a function selected from acid, ester, cyano functions and X represents a counter-ion, andthe thereby obtained sulfonium is hydrolyzed and2,4-dihydroxybutyric acid or its salt is cyclized into 2-hydroxybutyrolactone.
Toward functional polyester building blocks from renewable glycolaldehyde with sn cascade catalysis
Dusselier, Michiel,Van Wouwe, Pieter,De Smet, Sanne,De Clercq, Rik,Verbelen, Leander,Van Puyvelde, Peter,Du Prez, Filip E.,Sels, Bert F.
, p. 1786 - 1800 (2013/09/02)
Having been inspired by formose-based hypotheses surrounding the origin of life, we report on a novel catalytic route toward a series of recently discovered four-carbon α-hydroxy acids (AHA) and their esters from accessible and renewable glycolaldehyde (GA) in various solvents. The synthesis route follows a cascade type reaction network, and its mechanism with identification of the rate-determining step was investigated with in situ 13C NMR. The mechanistic understanding led to optimized reaction conditions with higher overall rates of AHA formation by balancing Bronsted and Lewis acid activity, both originating from the tin halide catalyst. An optimal H+/Sn ratio of 3 was identified, and this number was surprisingly irrespective of the Sn oxidation state. Further rate enhancement was accomplished by adding small amounts of water to the reaction mixture, boosting the rate by a factor of 4.5 compared with pure methanol solvent. The cascade reaction selectively yields near 60% methyl-4-methoxy-2- hydroxybutanoate (MMHB). In the optimized rate regime in methanol, an initial TOF of 7.4 molGA molSn-1 h-1 was found. In sterically hindered alcohols (isopropyl alcohol), the rate of AHA formation was even higher, and the corresponding vinyl glycolate esters arose as the main product. Vinyl glycolic acid, 2,4-dihydroxybutanoic acid, and its lactone were formed significantly in nonprotic solvent. The corresponding AHAs have serious potential as building blocks in novel biobased polymers with tunable functionality. The incorporation of vinyl glycolic acid in polylactic acid-based polyesters is illustrated, and postmodification at the vinyl side groups indeed allows access to a range of properties, such as tunable hydrophilicity, which is otherwise difficult to attain for pure poly(l-lactic acid).
TREATMENT OF SUGAR SOLUTIONS
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Page/Page column 12; 13; Sheets 5-8, (2008/06/13)
A process for treating a solution containing sugar and α-oxoaldehydes, comprising the step of adding a catalyst which comprises an optionally substituted histidine amino acid, such that the α-oxoaldehydes are catalytically converted to aldonic acids.
Alkaline degradation of monosaccharides V: Kinetics of the alkaline isomerization and degradation of monosaccharides
Bruijn, J. M. de,Kieboom, A. P. G.,Bekkum, H. van
, p. 35 - 43 (2007/10/02)
A new kinetic model for the alkaline isomerization and degradation of monosaccharides is presented which includes the interconversion of D-glucose, D-fructose, D-mannose and D-psicose.Computer simulations used in this model fit the experimental data and allow the determination of all relevant rate constants.Additionally, it has been established that, for the alkaline degradation of either D-fructose, D-glucose or D-mannose, substantial amounts of acidic products, i.e. ca. 65percent and ca. 20percent, are formed via D-fructose and D-psicose, respectively. - The influence of some reaction parameters on the pseudo-first-order rate constants involved in the kinetic model has been investigated.The enolization of monosaccharides appears to be the rate-limiting step in both the isomerization and the degradation reactions.The enolization rate is markedly enhanced at higher HO- concentration or by the addition of calcium(II).Direct retro-aldolization of D-fructose and D-psicose occurs at -> > 10-2 M or in the presence of calcium(II), leading to an additional increase in the degradation rate towards lactic acid.The shift of the isomerization equilibrium by borate towards D-fructose and D-psicose is accompanied by a decrease of the degradation rate constants, due to stabilization of the monosaccharides as their borate esters.
Alkaline degradation of monosaccharides III. Influence of reaction parameters upon the final product composition
Bruijn, J. M. de,Kieboom, A. P. G.,Bekkum, H. van
, p. 176 - 183 (2007/10/02)
A systematic investigation of the alkaline degradation of monosaccharides is presented.The influence of several parameters upon the degradation reaction has been determined by analysis of the reaction products using HPLC and, in some cases, GC.The HO- and the monosaccharide concentrations markedly influence the final product composition with respect to both the amount of C1 to C6 acids and the formation of oligomeric acidic products, the so-called > C6 acids.Maximum yields of these > C6 acids, up to 50 mol-C6-percent, are obtained at an HO- concentration of between 1E-3 M and 1E-2 Mwhen the monosaccharide concentration exceeds 1E-2 M.The presence of divalent calcium increases the retro-aldolization of monosaccharides in alkaline medium, as illustrated by the enhanched production of lactic acid, by complexation with, for instance, D-fructose.Borate partly protects monosaccharides against alkaline degradation through their borate esters, whilst the amount of saccharinic acids in the degradation product mixture is doubled.On the other hand, neither chloride and carbonate nor the reaction temperature influences the final product composition.Alkaline degradation experiments with pyruvaldehyde, glyceraldehyde and 1,3-dihydroxyacetone, all assumed to be reaction intermediates, indicate that aldolization of (di)carbonyl compounds causes the formation of substantial amounts of >C6 acids.
