𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Reaction of dichloroallose units in a chlorodeoxycellulose with lithium chloride under homogeneous conditions in N,N-dimethylacetamide

✍ Scribed by Ken-ichi Furuhata; Nobuyoshi Aoki; Shigeru Suzuki; Norihiro Arai; Munenori Sakamoto; Yasuo Saegusa; Shigeo Nakamura


Publisher
Elsevier Science
Year
1994
Tongue
English
Weight
617 KB
Volume
258
Category
Article
ISSN
0008-6215

No coin nor oath required. For personal study only.

✦ Synopsis


The reaction of methyl 3,6-dichloro-3,6-dideoxy+D-allopyranoside with lithium chloride in NJ-dimethylacetamide (DMA) was studied in relation to the possible conversion of 3,6-dichloro-3,6-dideoxy-D-allose units in a chlorodeoxycellulose during synthesis in a LiCI-DMA solvent system. Methyl 3,6-dichloro-3,6-dideoxy-/3-D-glucoside was formed; the reaction was reversible and the equilibrium was on the glucoside side. GLC analysis of the hydrolyzates of chlorodwcellulose samples after treatment with LiCl showed that the dichloroallose units were partly converted into 3,6-dichloro-3,6-dideoxy-D-glucose units. A kinetic study showed that the rate of conversion of the dichloroallose unit into the dichloroglucose unit was lower than that of the dichloroalloside into the dichloroglucoside, and the amounts of the two units at equilibrium were calculated to be close to each other. Based on the values of the kinetic parameters obtained, the conversion of the dichloroallose units into the dichloroglucose units during the chlorination of cellulose in LiCl-DMA was estimated to be negligibly small under typical reaction conditions.


πŸ“œ SIMILAR VOLUMES


Regioselective chlorination of chitin wi
✍ Munenori Sakamoto; How Tseng; Ken-ichi Furuhata πŸ“‚ Article πŸ“… 1994 πŸ› Elsevier Science 🌐 English βš– 781 KB

Purified chitin was chlorinated with an equimolar mixture of N-chlorosuccinimide and triphenylphosphine under homogeneous conditions in a 5% (w/v) solution of LiCl in N,N-dimethylacetamide at 70-85"C. 13C NMR spectroscopy of the chlorinated products and gas chromatographic-mass spectrometric analysi

Competitive formation of cellulose p-tol
✍ Charles L. McCormick; Timothy R. Dawsey; J.Kent Newman πŸ“‚ Article πŸ“… 1990 πŸ› Elsevier Science 🌐 English βš– 592 KB

The homogeneous preparation of a cellulose p-toluenesulfonate (tosylate) in N,N-dimethylaceta-mid+lithium chloride (DMAc-LiCl) is hampered by solvolysis of the p-toluenesulfonyl chloride (tosyl chloride). This Vilsmeier-Haack type reaction results in competitive formation of cellulosep-toluenesulfon

Bromination of regenerated chitin with N
✍ How Tseng; Ken-ichi Furuhata; Munenori Sakamoto πŸ“‚ Article πŸ“… 1995 πŸ› Elsevier Science 🌐 English βš– 623 KB

Chitin regenerated from LiCI-N,N-dimethylacetamide (DMA) was found to dissolve in 10 g/dL LiBr-DMA. The bromination of the regenerated chitin proceeded to a large extent (DS by bromine up to 0.94) with equimolar amounts of N-bromosuccinimide and triphenylphosphine under homogeneous conditions in LiB

Cellulose dissolution in lithium chlorid
✍ Guilherme A. Marson; Omar A. El Seoud πŸ“‚ Article πŸ“… 1999 πŸ› John Wiley and Sons 🌐 English βš– 229 KB πŸ‘ 2 views

Rate constants and activation parameters for decrystallization of Avicel PH-101 cellulose, and bagasse-based cellulose in presence of LiCl/N,N-dimethylacetamide solvent system have been determined from dependence of the index of crystallinity of cellulose, Ic, on time, under nonisothermal conditions