A kinetic analysis of the reactivities of the hydroxyl groups in formylation of the D-glucopyranosyl residues in dextrin

Rowland, Stanley P.; Brannan, Mary Ann F.; Janssen, Henrike; Pittman, P. F.

doi:10.1016/s0008-6215(00)82212-0

Cited by 5 publications

(12 citation statements)

References 20 publications

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“…In practice we have previously proposed 17 that some species only appear in minor amounts, like the 2-acyl-[GS] species, and that primary alcohols form esters faster than secondary alcohols. 28,29 It is important to point out that the combination of NMR and mass spectroscopies gives a much clearer picture of the PGS prepolymer than the use of either method alone. For example, both 1-acyl-[GS] and 2-acyl-[GS] will have the same molecular ion at approximately 276 Da in the individual mass spectra (though with the spectra of the pure compounds a slightly different fragmentation pattern may appear in the electron ionization mass spectrum analysis).…”

Section: Pgs Prepolymer Synthesismentioning

confidence: 99%

“…All three techniques show that during PGS prepolymer syntheses, as explained in Scheme 1, further acylation usually leads to longer oligomers rather than branched molecules and this is consistent with the lower reactivity of the secondary versus the primary hydroxyl group. 28,29 Thus, three different series are observed, namely the [(GS) n G] series, [S(GS) n ] series and [(SG) n ] series, each having a difference in mass from one oligomer to another of 258.1467 amu (rounded to 258 amu in Scheme 3). There are also substantial amounts of cyclic molecular species present that mass spectrometry can structurally identify as being of the form of [(GS) n -cycloGS] and [(SG) n S-cycloGS] series (the isomeric form is not identifiable), but which cannot be differentiated analytically with 13 C NMR spectroscopy because the cyclic esters are not distinguishable from all the acyclic glycerol esters (Scheme 2).…”

Section: Nmr Analyses Of Pgs Prepolymermentioning

confidence: 99%

“…However, some highly substituted xylitols are unlikely to form, because as a general rule primary alcohols have a preference to form esters first. 28,29 Of course racemic mixtures of chiral molecules (including oligomers) can form, but will not show up in either NMR or mass spectral analyses, and therefore will not be further discussed or displayed in schemes in either the text or supporting information.…”

Section: Pxs Prepolymer and Pxs Gel Synthesis Of Pxs Prepolymer And Pmentioning

confidence: 99%

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Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

Moorhoff

Cook

et al. 2014

Polymer International

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Atmospheric pressure chemical ionization (negative ion) and electrospray ionization (positive and negative ion) mass spectrometry and nuclear magnetic resonance ( 1 H NMR and 13 C NMR) were used to characterize the prepolymer (i.e. uncrosslinked) poly(xylitol sebacate) (PXS), prepared by condensation of xylitol [X] and sebacic acid [S], and this was compared with poly(glycerol sebacate) (PGS), prepared by condensation of glycerol [G] and [S]. The PXS prepolymer, prepared at 118 ∘ C/24 h, gave predominantly 1-acyl-[XS] and 1,5-diacyl-[SXS] species and smaller amounts of 2-acyl substitutions. At 130 ∘ C/24 h an increase of the amount of the 1-acyl and 1,5-diacyl substitutions in the [(SX) n ], [S(XS) n ] and [(XS) n X] series was identified, as was found for the analogous PGS prepolymer ([(SG) n ], [S(GS) n ] and [(GS) n G] series). Novel tetrahydrofuranyl species were found in the PXS prepolymer. Further polymerization of the PXS prepolymer gave a gel which when analysed using 13 C NMR was shown to mainly contain 1-acyl and 1,5-diacyl substitutions.

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Section: Pgs Prepolymer Synthesismentioning

confidence: 99%

Section: Nmr Analyses Of Pgs Prepolymermentioning

confidence: 99%

Section: Pxs Prepolymer and Pxs Gel Synthesis Of Pxs Prepolymer And Pmentioning

confidence: 99%

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Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

Moorhoff

Cook

et al. 2014

Polymer International

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“…Several studies reported here have relied heavily on these techniques. , This report summarizes a series of recent explorations in measurements of the relative distributions of substituent groups on the 2-0-, 3-0-, and 6-0-positions of the D-glucohyranosyl unit [3,7,12,13,14]. To put this work in proper perspective, major .…”

Section: Introductionmentioning

confidence: 99%

“…Curve A is 3-0-allyl-D-glucopyranose ; curve B is 2-0-allyl-D-glucopyranose; curve C is 6-0-allyl-D-glucopyranose ; and curve D is the concentrate from fermentation of the hydrolyzate of allyl cellulqse.Formylation of Dextrin[ 13) ].…”

mentioning

confidence: 99%

The Relative Reactivities of the Hydroxyl Groups of Cotton Cellulose—A Progress Report1

Rowland

Bullock

Cirino

et al. 1967

Textile Research Journal

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Major preceding studies of the distribution of substituents in cellulose have been reviewed. Over-all results indicate that the highest degree of reaction occurs at the hydroxyl group on C-2 in the case of the irreversible Williamson syntheses involving reagents of small molecular size. Pronounced preferential reaction occurs at the hydroxyl group on C-6 in the case of reversible reactions and with increasing molecular size of reagent.The relative reactivities of the hydroxyl groups on C-2, C-3, and C-6 of the D (1→4)-β-glucopyranosyl unit of cotton cellulose have been explored with three chemical agents.Predominant reaction of cotton cellulose occurs at the primary hydroxyl group on C-6 in the case of the reversible Michael addition of methyl vinyl sulfone (i.e., 2-0-: 3-0-: 6-0-= 0.20: 0.03: 1.00), at the hydroxyl groups on C-2 and C-6 in the case of the irreversible reaction with diethylaminoethyl chloride (1.27 : 0.35 : 1.00), and at the hydroxyl groups on C-6 and C-2 in the case of the irreversible Williamson synthesis with sodium allyl sulfate (0.7:0.2:1.0). The D -(1→4)-α-glucopyranosyl unit of dextrin (employed as a soluble model compound for cellulose) undergoes reversible esterification with formic acid most rapidly and to the highest equilibrium level at the primary hydroxyl group on C-6.-

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Synthesis, characterization and properties of biocompatible poly(glycerol sebacate) pre‐polymer and gel

Li¹,

Cook

Moorhoff

et al. 2012

Polymer International

107

139

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Poly(glycerol sebacate) (PGS) is an elastomer with potential biomedical applications but it suffers from problems with irreproducible synthesis and the unacceptable toxicity of very soft PGS elastomers. To establish the reason for these problems, PGS was synthesized using different temperatures and reaction times, and the reaction was monitored by titration of the unreacted carboxylic groups and measurement of the mass loss during synthesis. It was found that evaporation of glycerol was a major cause of irreproducibility of the elastomer synthesis and this was more significant at higher reaction temperatures. The polymer microstructure was analysed using NMR spectroscopy and all twelve acylglyceride 13C‐signals as well as two small extra peaks of the residual glycerol were observed for the pre‐polymer. For the PGS gel, the glyceride moieties were characterized using NMR spectroscopy for the first time. The modulus and ultimate tensile strength of the gel increased with longer cure times and at higher cure temperatures while the elongation to break decreased and this was interpreted in terms of network theory. The cell viability of mouse fibroblasts was better for PGS samples with a higher conversion.© 2012 Society of Chemical Industry

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A kinetic analysis of the reactivities of the hydroxyl groups in formylation of the D-glucopyranosyl residues in dextrin

Cited by 5 publications

References 20 publications

Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

The Relative Reactivities of the Hydroxyl Groups of Cotton Cellulose—A Progress Report1

Synthesis, characterization and properties of biocompatible poly(glycerol sebacate) pre‐polymer and gel

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