Anhydrosugar synthesis

Patent metadata

Field	Value
Publication number	US-10364265-B1
Application number	US-201615380030-A
Country	US
Kind code	B1
Filing date	Dec 15, 2016
Priority date	Dec 15, 2015
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

Improved methods of making anhydrosugars by pyrolysis of a substrate sugar to remove at least one water molecule thereby producing a desired anhydrosugar and side products, the improvement being either 1) protecting one hydroxyl group of the substrate sugar before pyrolysis; or (2) pretreating the substrate sugar with a metal salt and optional acid before pyrolysis, wherein lower amounts of said side products are produced by said improved method.

First claim

The invention claimed is:

1. A method of making an anhydrosugar, comprising:
a) dissolving a carbohydrate substrate in a solvent;
b) performing a Fischer glycosidation on the C1 carbon of said carbohydrate substrate by reacting said dissolved sugar substrate with an alcohol in the presence of a solid acid catalyst, wherein said Fischer glycosidation adds the alcohol on said C1 carbon as an ether;
c) removing said solid acid catalyst and said solvent to form a solid sample; and,
d) performing heat treatment on said solid sample to produce a desired anhydrosugar.

2. The method of claim 1 , wherein said heat treatment occurs at about 350° C. to 600° C.

3. The method of claim 1 , wherein said alcohol is alkane or aryl based.

4. The method of claim 1 , wherein said solid acid catalyst is Amberlyst-15.

5. The method of claim 1 , wherein said ether has a methyl or phenyl group.

6. The method of claim 1 , wherein said carbohydrate substrate is one or more of the following: mannose, galactose, allose, talose, glucose, pentose, hexose, sucrose, maltose, lactose, cellobiose, maltodextrins, starches, cellulose, lignocellulose, and derivatives thereof.

7. The method of claim 1 , wherein said carbohydrate substrate is a polymeric sugar and where the method is preceded by a step converting said polymeric sugar to one or more simple sugars.

8. The method of claim 1 , wherein the desired anhydrosugar is levoglucosan (C 6 H 10 O 5 ), mannosan (C 6 H 10 O 5 ), galactosan (C 6 H 10 O 5 ), levoglucosone (C 6 H 6 O 3 ) or 5-hydroxymethylfurfural (C 6 H 6 O 3 ), furfural, 1,4;3,6-Dianhydroglucose, anhydroglucofuranose or combinations thereof.

Assignees

• William Marsh Rice Univeristy
• Univ Rice William M

Inventors

• Chen Li
• Wong Michael S
• Zhang Zongchao

Classifications

• C07D307/44

  Furfuryl alcohol · CPC title

• C07D493/18

  Bridged systems · CPC title

• C07D493/08

  Bridged systems · CPC title

• C07H3/10 Primary

  Anhydrosugars, e.g. epoxides · CPC title

• C07H1/00

  Processes for the preparation of sugar derivatives · CPC title