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US4421568A
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Process for making L-sugars and D-fructose
Assignee: IFP Energies nouvelles
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Filing: 1981-08-26
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Granted: 1983-12-20
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Expires: 2001-08-26
Abstract
Abstract A method for producing L-sugars including L-idose and L-gulose as well as D-fructose from D-glucose. The method comprises epimerizing D-glucose to a mixture of D-glucose and D-mannose, hydrogenating the mixture in a fixed catalyst bed to provide D-sorbitol and D-mannitol, separating the D-mannitol by fractional crystallization, oxydizing separately the D-sorbitol and D-mannitol to provide L-sorbose and D-fructose, respectively; and racemizing the L-sorbose in a weak alkaline solution to provide a mixture of L-sorbose, L-idose and L-gulose, and precipitating the remaining L-sorbose with a dilute lime solution. The unconverted L-sorbose is recovered and recycled.
Inventors
- 👤 Derk T. A. Huibers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:23
CPC Classifications
C; C07; C07H; C07H3/00; C07H3/02; C12; C12P; C12P19/00; C12P19/02; C13; C13K; C13K11/00; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/822; Y10S435/823
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
91 words
A method for producing L-sugars including L-idose and L-gulose and D-fructose from D-glucose which comprises the steps of: (a) epimerizing D-glucose to a mixture of D-glucose and D-mannose; (b) hydrogenating said D-glucose mixture to provide L-sorbitol and D-mannitol; (c) separating said D-mannitol from said D-sorbitol; (d) oxidizing separately said D-sorbitol and D-mannitol to provide L-sorbose and D-fructose, respectively; (e) racemizing said L-sorbose to provide a mixture of L-sorbose, L-idose and L-gulose; and (f) precipitating the remaining L-sorbose with lime from a dilute solution of said mixture of L-sorbose, L-idose, and L-gulose.
Claim 2
Independent Claim
91 words
A method for producing L-sugars including L-idose and L-gulose and D-fructose from D-glucose which comprises the steps of: (a) epimerizing D-glucose to a mixture of D-glucose and D-mannose; (b) hydrogenating said D-glucose mixture to provide L-sorbitol and D-mannitol; (c) separating said D-mannitol from said D-sorbitol; (d) oxidizing separately said D-sorbitol and D-mannitol to provide L-sorbose and D-fructose, respectively; (e) racemizing said L-sorbose to provide a mixture of L-sorbose, L-idose and L-gulose; and (f) precipitating the remaining L-sorbose with lime from a dilute solution of said mixture of L-sorbose, L-idose, and L-gulose.
Claim 3
Dependent Claim
24 words
The method according to claim 1, wherein the epimerization of said D-glucose takes place in a fixed catalyst bed of silicotungstic acid or silicagel.
Claim 4
Dependent Claim
12 words
The method according to claim 1, wherein any unconverted L-sorbose is recycled.
Claim 5
Dependent Claim
16 words
The method according to claim 1, wherein said D-glucose is a 10 to 70% aqueous solution.
Claim 6
Dependent Claim
31 words
The method according to claim 1, wherein said mixture of D-glucose and D-mannose is hydrogenated in a fixed catalyst bed at a temperature ranging from about 100° to about 150° C.
Claim 7
Dependent Claim
18 words
The method according to claim 1, wherein said L-sorbose is precipitated in a 6 to 7% lime solution.
Claim 8
Dependent Claim
17 words
The method according to claim 1, wherein said L-sorbose is racemized in a 1.0 N alkaline solution.
Claim 9
Dependent Claim
25 words
The method according to claim 1, wherein the oxidation of L-sorbose is carried out with an oxygen containing gas in the presence of Gluconobacter suboxydans.
Claim 10
Dependent Claim
27 words
The method according to claim 1, wherein the oxidation of D-mannitol to D-fructose is carried out with an oxygen containing gas in the presence of Gluconobacter suboxydans.
Claim 11
Dependent Claim
22 words
The method according to claim 1, wherein the L-idose and L-gulose are recovered by crystallization after removal of the L-sorbose with lime.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |