608-55-9

Upstream product

• 10323-20-3 D-Arabinose 
• 2438-80-4 L-Fucose 
• 488-30-2 arabinoic acid 
• 685-73-4 D-galacturonic acid 
• 576-37-4 glucuronic acid 
• 57-50-1 Sucrose 
• 6556-12-3 D-glucuronic acid 
• 7697-37-2 nitric acid 
• 15384-34-6 D-lyxono-1,4-lactone 
• 87-79-6 L-sorbose 
• 608-53-7 L-arabinonic acid 
• 6014-42-2 L-rhamnose 
• 5328-37-0 L-arabinose 
• 488-73-3 (+)-proto-quercitol 

Downstream Products

• 488-31-3 dl-trioxyglutaric acid 
• 1436-59-5 cis-cyclohexane-1,2-diamine 
• 110-94-1 1,5-pentanedioic acid 

Relevant academic research and scientific papers

Rate-limiting steps in bromide-free TEMPO-mediated oxidation of cellulose - Quantification of the N-Oxoammonium cation by iodometric titration and UV-vis spectroscopy

A iodometric titration method was introduced to study the conversion of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) to the corresponding N-oxoammonium cation (TEMPO+) by hypochlorite in the absence and presence of bromide ion. The validity of the titration was verified with UV-vis spectroscopy combined with a multivariate curve resolution (MCR) algorithm to calculate the concentrations and spectral signatures of the pure components (i.e., TEMPO, Cl(+1) and TEMPO+). The formation of the oxoammonium cation was successfully followed during the activation of TEMPO by HOCl and HOBr. It was found that HOBr is a more effective activator for TEMPO than HOCl is. Moreover, the importance of a separate activation step for TEMPO with bromide-free TEMPO oxidations could be identified with this titration method. The content of TEMPO+ was also monitored during the TEMPO-mediated oxidation of a cellulosic pulp by hypochlorite in the absence and presence of bromide. It was found that the oxidation of the alcoholic groups by TEMPO+ was generally the rate-determining step and much slower than the regeneration of TEMPO+ through oxidation of the hydroxylamine by HOCl and HOBr. However, at high pH the latter reaction became rate-limiting.

PROCESSES FOR PREPARING ALDARIC, ALDONIC, AND URONIC ACIDS

Various processes for preparing aldaric acids, aldonic acids, uronic acids, and/or lactone(s) thereof are described. For example, processes for preparing a C2-C7 aldaric acid and/or lactone(s) thereof by the catalytic oxidation of a C2-C7 aldonic acid and/or lactone(s) thereof and/or a C2-C7 aldose are described.

Aerobic oxidation of xylose to xylaric acid in water over pt catalysts

Energy-efficient catalytic conversion of biomass intermediates to functional chemicals can make bio-products viable. Herein, we report an efficient and low temperature aerobic oxidation of xylose to xylaric acid, a promising bio-based chemical for the production of glutaric acid, over commercial catalysts in water. Among several heterogeneous catalysts investigated, Pt/ C exhibits the best activity. Systematic variation of reaction parameters in the pH range of 2.5 to 10 suggests that the reaction is fast at higher temperatures but high C C scission of intermediate C5-oxidized products to low carbon carboxylic acids undermines xylaric acid selectivity. The C C cleavage is also high in basic solution. The oxidation at neutral pH and 60 8C achieves the highest xylaric acid yield (64 %). O2 pressure and Pt amount have significant influence on the reactivity. Decar-boxylation of short chain carboxylic acids results in formation of CO2, causing some carbon loss; however, such decarboxyla-tion is slow in the presence of xylose. The catalyst retained comparable activity, in terms of product selectivity, after five cycles with no sign of Pt leaching.

Efficient chiral resolution of (±)-cyclohexane-1,2-diamine

A novel and efficient method has been developed for the chiral resolution and separation from cis-cyclohexane-1,2-diamine of (±)-cyclohexane-1,2- diamine, which reacts with xylaric acid, a substitute for tartaric acid. This method provides (1R,2R)-cyclohexane-1,2-diamine, and (1S,2S)-cyclohexane-1,2- diamine and cis-cyclohexane-1,2-diamine in good yield with high optical purity.

Pentaric acids and derivatives from nitric acid-oxidized pentoses

This report describes the preparation of the four stereoisomeric pentaric acids by nitric acid oxidation of d-xylose, d-arabinose, l-arabinose, and d-ribose, with xylaric, d-arabinaric, and l-arabinaric acids being made in a reactor under computer control. The pentaric acids were converted to their crystalline N,N′-dimethylpentaramides, derivatives that proved useful for isolation of the arabinaric acids from their respective oxidation mixtures. The N,N′-dimethylpentaramides were readily convertible to the corresponding pentaric acid disodium salts in aqueous sodium chloride. The 2,3,4-O-triacetyl-N,N′-dimethylpentaramides of xylaric, l-arabinaric, and ribaric acid were also prepared. Ribaric acid was isolated as crystalline 1,4(5,2)-ribarolactone and further characterized by x-ray crystallography.

The use of N,N′-diallylaldardiamides as cross-linkers in xylan derivatives-based hydrogels

N,N′-Diallylaldardiamides (DA) were synthesized from galactaric, xylaric, and arabinaric acids, and used as cross-linkers together with xylan (X) derivatives to create new bio-based hydrogels. Birch pulp extracted xylan was derivatized to different degrees of substitution of 1-allyloxy-2-hydroxy-propyl (A) groups combined with 1-butyloxy-2-hydroxy-propyl (B) and/or hydroxypropyl (HP) groups. The hydrogels were prepared in water solution by UV induced free-radical cross-linking polymerization of derivatized xylan polymers without DA cross-linker (xylan derivative hydrogel) or in the presence of 1 or 5 wt % of DA cross-linker (DA hydrogel). Commercially available cross-linker (+)-N,N′-diallyltartardiamide (DAT) was also used. The degree of substitution (DS) of A, B, and HP groups in xylan derivatives was analyzed according to 1H NMR spectra. The DS values for the cross-linkable A groups of the derivatized xylans were 0.4 (HPX-A), 0.2 (HPX-BA), and 0.4 (X-BA). The hydrogels were examined with FT-IR and elemental analysis which proved the cross-linking successful. Water absorption of the hydrogels was examined in deionized water. Swelling degrees up to 350% were observed. The swollen morphology of the hydrogels was assessed by scanning electron microscopy (SEM). The presence of cross-linkers in DA hydrogels had only a small impact on the water absorbency when compared to xylan derivative hydrogels but a more uniform pore structure was achieved.

Reaction pathways of glucose oxidation by ozone under acidic conditions

The ozonation of d-glucose-1-13C, 2-13C, and 6-13C was carried out at pH 2.5 in a semi-batch reactor at room temperature. The products present in the liquid phase were analyzed by GC-MS, HPAEC-PAD, and 13C NMR s

The reaction of hyaluronic acid and its monomers, glucuronic acid and N- acetylglucosamine, with reactive oxygen species

Synovial fluid is a ~0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.

THE CONVERSION OF D-XYLOSE TO XYLITOL AND D-XYLONIC ACID BY A BOVINE LENS PREPARATION

Incubation of D-xylose with an aqueous solution of bovine lens protein (100 mg/mL) at 37 deg C and pH 7.0 gives both a reduced product (xylitol) and an oxidation product (D-xylonic acid), which were both unequivocally identified by GLC (TMS ether derivative) and by GLC/MS.Studies of the reaction at a variety of conditions suggest that both the reduction and oxidation reactions are protein (possibly enzyme) catalyzed and appear to be unique to lens protein (albumin and ovalbumin do not catalyze the reaction).

Kinetics and Mechanism of Oxidation of Xylitol and Galactitol by Hexacyanoferrate(III) Ion in Aqueous Alkaline Medium

Kinetics of oxidation of xylitol and galactitol by hexacyanoferrate(III) ion in aqueous alkaline medium is reported.The reaction rate is of first order with respect to hexacyanoferrate(III) in each substrate.The reaction is first order at lower concentrations of xylitol and galactitol and tends towards zero order as the concentration increases.Similarly first order kinetics was obtained with respect to hydroxide ion at lower concentrations and tends to lower order at higher concentration in the oxidation of xylitol; in the oxidation of galactitol the reaction isfirst order with respect to hydroxide ion even up to manyfold variation.The course of reaction has been considered to proceed through the formation of an activated complex between (2-) and substrate anion which decomposes slowly into radical and (3-).A probable reaction mechanism is proposed. - Keywords: Galactitol; Kinetics; Mechanism; Oxidation; Reduction; Xylitol