Cationic Ring-Opening Polymerization of 3,6-Di-<i>O</i>-benzyl-α-<scp>d</scp>-glucose 1,2,4-Orthopivalate and the First Chemical Synthesis of Cellulose

Nakatsubo, Fumiaki; Kamitakahara, Hiroshi; Hori, Michiko

doi:10.1021/ja953286u

Cited by 126 publications

(109 citation statements)

References 33 publications

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“…After the reaction, these groups were replaced by acetyl groups, which were removed in a last step to give pure cellooctaose with a yield of 87%. In 1996 Nakatsubo et al [39] succeeded in performing the first cellooligosaccharide synthesis via cationic ringopening polymerization. The reaction, performed with 3,6-di-O-benzyl-α-D-glucose 1,2,4-orthopivalate and the aid of a triphenylcarbenium tetrafluoroborate initiator, was shown to be highly stereoselective.…”

Section: Chemical Synthesismentioning

confidence: 99%

Preparation and Analysis of Cello- and Xylooligosaccharides

Vejdovszky

Oberlerchner

Zweckmair

et al. 2015

Advances in Polymer Science

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This review provides a general overview of preparation, separation, and analytical methods for cello-and xylooligosaccharides. Arising as side-stream products of different biorefinery processes, these compounds have increasingly gained the interest of researchers and engineers in the last few decades. Beside their application as additives in the food, feed, and pharmaceutical industries, these oligomeric carbohydrates are of key importance as model compounds for studying the dependence of physicochemical properties on the degree of polymerization (DP). First, different preparation methods for mixtures of oligosaccharides with DPs between 1 and 30 are discussed. These methods include acetolysis, acid and enzymatic hydrolysis, and glycoside synthesis. Then, separation techniques, including size exclusion chromatography, normal phase and hydrophilic interaction chromatography, and chromatography on cation exchange resins, are presented. Analysis of oligosaccharides by different techniques is described.

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Section: Chemical Synthesismentioning

confidence: 99%

Preparation and Analysis of Cello- and Xylooligosaccharides

Vejdovszky

Oberlerchner

Zweckmair

et al. 2015

Advances in Polymer Science

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“…Benzyl and pivaloyl groups are usually used as temporary protective groups for the syntheses of regioselective functionalization of cellulose. [15,16] The results of the ring-opening polymerizations of compounds 4, 5, and 6 are summarized in Table 1. The molecular weights of polymerization products 7, 11, 12-1, 12-2 and 12-3 were different to each other.…”

Section: Synthesis Of 2-o- 3-o-and 6-o-ethyl Cellulosesmentioning

confidence: 99%

“…20, and was synthesized after many trials. [15] One and three polymerization conditions were carried out for 3EC (2) and 6EC (3), respectively. Run 4 has been reported in our previous paper.…”

Section: Synthesis Of 2-o- 3-o-and 6-o-ethyl Cellulosesmentioning

confidence: 99%

Synthesis and Structure/Property Relationships of Regioselective 2‐O‐, 3‐O‐ and 6‐O‐Ethyl Celluloses

Kamitakahara

Funakoshi

Nakai

et al. 2010

Macromolecular Bioscience

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Regioselectively ethylated celluloses, 2-O- (1), 3-O- (2), and 6-O-ethyl- (3) celluloses were synthesized via ring-opening polymerization of glucopyranose orthopivalate derivatives. The number-average degrees of polymerization (DP(n)s) of compounds 1 and 2 were calculated to be 10.6 and 49.4, respectively. Three kinds of compound 3 with different DP(n)s were prepared: DP(n)s = 12.9 (3-1), 60.3 (3-2), and 36.1 (3-3). The 2-O-, 3-O-, and 6-O-ethylcelluloses were soluble in water, confirmed by NMR analysis. Furthermore, the 3-O- (2), and 6-O-ethyl- (3-2) celluloses showed thermo-responsive aggregation behavior and had a lower critical solution temperature (LCST) at about 40 degrees C and 70 degrees C, respectively, based on the results from turbidity tests and DSC measurements. The 6-O-ethyl-cellulose (3-3) with DP(n) = 36.1 and DP(w) = 54.6 showed gelation behavior over approx 70 degrees C, whereas the 6-O-ethyl-celluloses 3-1 and 3-2 with lower and higher molecular weight, such as DP(n)s 12.9 and 60.3, did not show gelation behavior at this temperature. It was revealed that the position of ethyl group affected the phase transition temperature. According to our experiments, the 3-O-ethyl and 6-O-ethyl groups along the cellulose chains caused the thermo-responsive property of their aqueous solutions. The appropriate DP of the regioselective 6-O-ethyl-cellulose existed for gelation of the aqueous solution.

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“…1 Not only these rigid structures were used for conformational studies of pyranoses, 2,3 but also proved to be of utility for the synthesis of the carbohydrate moiety present in bleomycin group antibiotics 4 and for the preparation of novel materials as well. In this regards, Nakatsubo reported the first synthesis of modified cellulose by cationic ring-opening polymerization of 3,6-di-O-benzyl-α-D-glucopyranose 1,2,4-orthopivalate, 5 with high stereoselectivity for the formation of (1→4)-β-glucosidic linkages and in high yield; 6 therefore derivatives of α-D-glucopyranose 1,2,4-orthoesters can be considered valuable building blocks for the design of advanced materials from cellulose. 7 Described herein is the preparation of α-D-glucopyranose 1,2,4-orthoacetates, of potential utility as synthetic intermediates for highly functionalized cellulose.…”

Section: Introductionmentioning

confidence: 99%