Harumi Kaga

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Large-scale microwave rapid pyrolysis of cellulosic materials has been investigated. Levoglucosan (1,6-anhydro-β-d-glucopyranose) was obtained from a larch log as the main anhydrosugar in 2.6% yield on the basis of dry wood weight. This yield would be much higher than that obtainable by conventional pyrolysis in the largescale reaction. Levoglucosenone(More)
4-Vinylbenzyl maltohexaoside peracetate (1) was copolymerized with divinylbenzene (DVB) using 1-phenyl-1-(2',2',6',6'-tetramethyl-1'-piperidinyloxy)ethane (2) in m-xylene. The copolymerizations were performed at 138 degrees C for 20 h using the mole fraction of 1 in the total feed of 1 and DVB (F1: [1]/[1]+[DVB]) varying from 0.11 to 0.38, affording(More)
Synthetic polysaccharides, (1-->6)-alpha-D-glucopyranan (3a) and (1-->6)-alpha-D-mannopyranan (3b), were prepared by the cationic ring-opening polymerization of 1,6-anhydro-2,3,4-tri-O-allyl-beta-D-glucopyranose (1a) and 1,6-anhydro-2,3,4-O-6-allyl-beta-D-mannopyranose (1b), followed by the cleavage of the allyl ether linkage of(More)
An aqueous solution of glucose was reacted at temperatures from 200 to 400 degrees C under atmospheric pressure using a continuous flow reactor. For reaction temperatures above 300 degrees C, the liquid product yield was not sensitive to the temperature change; on the other hand, below 300 degrees C, it decreased rapidly with decreasing temperature.(More)
For the synthesis of protopine alkaloids, we studied a reaction sequence based on a ring enlargement of indeno[2,1-a][3]benzazepines by a singlet oxygen oxygenation, followed by conversion of an amide carbonyl group of the resultant 10-membered keto-lactam to a methylene group, which is the last step for completion of the synthesis. The key substances,(More)
Introduction The symposium on the chemistry of biocatalysis was held on 11 and 12 December 2002 in Hokkaido. Approximately 98 researchers from industry and academic world and 51 students participated to the symposium. We had the following program: Special lecture: Professor S. Kinoshita (Graduate School of Engineering, Hokkaido University, Japan);(More)
1,6-Anhydro-D-hexofuranoses, such as 1,6-anhydro-β-D-glucofuranose (1), 1,6-anhydro-β-D-mannofuranose (2), and 1,6-anhydro-α-D-galactofuranose (3), were polymerized using a thermally induced cationic catalyst in dry propylene carbonate to afford hyperbranched polysaccharides (poly1-3) with degrees of branching from 0.40 to 0.46. The weight-average molecular(More)
The application of high temperature water to produce levoglucosan from glucose was studied. The reactions were performed using a tube reactor, and the kinetics for the decomposition of glucose and levoglucosan in high temperature water was examined. The temperature dependence of the reaction rate of the glucose decomposition was of the Arrhenius type. In(More)
A water-insoluble, extracellular polysaccharide was isolated from the culture medium of the snow mold fungus, Microdochium nivale, that had been cultivated in potato/dextrose broth. The polysaccharide consisted of glucose only. Its Fourier transform infrared spectrum showed a beta configuration of the C1 position of glucose. Linkage analysis of the(More)