1214839-99-2Relevant articles and documents
Selective dehydration of sorbitol to 1,4-anhydro-d-sorbitol catalyzed by a polymer-supported acid catalyst
Xiu, Yuhe,Chen, Angjun,Liu, Xuerui,Chen, Chen,Chen, Jizhong,Guo, Li,Zhang, Ran,Hou, Zhenshan
, p. 28233 - 28241 (2015/04/14)
Novel polymer-supported Bronsted acid polymer catalysts have been successfully synthesized by radical polymerization, followed by a simple solvothermal route and ion exchange step. The as-synthesized co-polymers were characterized by Elemental Analysis, FT-IR spectroscopy, thermogravimetric analysis and scanning electron microscopy and then were employed as a heterogeneous catalyst for dehydration of sorbitol. Especially, the polymer catalysts have a unique advantage of adjustable Bronsted acidity, and the polymer with 1.82 mmol g-1 of Bronsted acidity was a very efficient catalyst for highly selective dehydration of sorbitol into 1,4-anhydro-d-sorbitol. The dehydration reaction can be completed within 4 h and the selectivity of 1,4-anhydro-d-sorbitol achieved 90%. Moreover, the present catalysts resisted acid-leaching and can be recycled in five consecutive cycles without obvious loss of activity. This journal is
MECHANISMS OF PYROLYSIS OF POLYSACCHARIDES: CELLOBIITOL AS A MODEL FOR CELLULOSE
Lowary, Todd L.,Richards, Geoffrey N.
, p. 79 - 89 (2007/10/02)
The pyrolysis of cellobiitol has been studied as a model for cellulose.The products were determined from pyrolysis at 350 deg C in vacuo and at 350 deg C and at 171 deg C at atmospheric pressure.In vacuo, a 32percent yield of 1,6-anhydro-β-D-glucopyranose (levoglucosan 5) and a 70percent yield of D-glucitol and its anhydrides were obtained, but under atmospheric pressure these yields were much lower.A mechanism is postulated in which the first step in the pyrolysis is a heterolytic scission of the glucosidic linkage to produce a glucosyl cation and a glucitol anion.The formeryields the volatile levoglucosan by intramolecular attack of O-6 on the C-1 cation and this reaction is favored in vacuo because of the resultant efficient removal of 5.The glucitol is obtained predominantly as anhydrides, which are volatile in the vacuum pyrolysis.Lower tempeature (171 deg C) pyrolysis gave no 5.The glucosyl cation under such conditions is believed to undergo intermolecular nucleophilic substitution with hydroxyl groups from unreacted starting material and from glucitol to produce oligosaccharides.
