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Method for preparing 2,3,4,5,6-5-O-benzyl mannose from D-mannitol

A technology of mannitol and mannose, which is applied in 2 fields, can solve the problems of environmental pollution, mannose is not cheap, mercaptan odor, etc., and achieve the effect of reducing pollution, low price and mild reaction conditions

Inactive Publication Date: 2009-07-08
CHANGZHOU NIUTANG CHEM PLANT CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional preparation method mostly uses mannose as raw material, which is obtained through thiol protection of aldehyde groups, benzylation of hydroxy groups, and selective dethiol protection. The disadvantages are obvious: 1. Mannose is not cheap; 2. Sulfur Alcohol has a strong odor, which is easy to cause environmental pollution; 3. The efficient method of desulfurization is the mercuric chloride method, which is highly toxic and has serious pollution to the environment

Method used

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  • Method for preparing 2,3,4,5,6-5-O-benzyl mannose from D-mannitol

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preparation example Construction

[0007] The invention discloses a method for preparing 2,3,4,5,6-penta-O-benzylmannose from D-mannitol, which comprises the following steps:

[0008] Step 1: Prepare 1-trityl mannitol, dissolve D-mannitol in excess dry pyridine, add triphenylchloromethane, after the reaction is completed, extract, dry, and perform silica gel column chromatography to obtain 1-trityl Mannitol;

[0009] Step 2: Prepare 2,3,4,5,6-penta-O-benzyl-1-trityl mannitol, add 1-trityl mannitol and chlorobenzyl to NaH, dry DMF, react After steam distillation, extraction, washing, drying and silica gel column chromatography, 2,3,4,5,6-penta-O-benzyl-1-trityl mannitol was obtained;

[0010] Step 3: Preparation of 1,2,3,4,5-penta-O-benzylmannitol to CH 2 Cl 2 , MeOH dissolved 2,3,4,5,6-penta-O-benzyl-1-trityl mannitol, add BF 3 ·Et 2 O solution reaction, extraction, washing and drying to obtain 1,2,3,4,5-penta-O-benzylmannitol;

[0011] Step 4: Preparation of 2,3,4,5,6-penta-O-benzylmannose to CrO 3 , py...

Embodiment 1

[0020] Add 5.0g (27.5mmol) D-mannitol and 100mL anhydrous pyridine into a 250mL round bottom flask, stir and dissolve until the solution is clear, add 3.8g (13.6mmol) triphenyl in 10 times in 3 hours under ice bath methyl chloride. After 2 hours of reaction in ice bath, the temperature was raised to 80° C. for 14 hours. Concentrate to remove pyridine (toluene is co-evaporated), add 30mL water to dissolve the reaction mixture, and sequentially extract with 5×40mL dichloromethane (the combined aqueous phase is concentrated and dried to recover unreacted mannitol), and the organic phase Na 2 SO 4 Drying, filtration, concentration, and silica gel column chromatography (V (petroleum ether): V (ethyl acetate) = 4:1 → 2:1 → ethyl acetate elution) gave 3.2 g of colorless syrupy 1-triphenyl Methylmannitol (55% yield from triphenylchloromethane).

[0021] 4.8g (0.2mol) of NaH, 50mL of anhydrous DMF, heated at 50°C, and dropwise added 23mL (0.2mol) of BnCl to the system while stirring...

Embodiment 2

[0025] Add 5.0g (27.5mmol) D-mannitol and 100mL anhydrous pyridine into a 250mL round-bottomed flask, stir and dissolve until the solution is clear, add 2.5g (9.0mmol) triphenylchloromethane at room temperature, and react for 3d at room temperature . Concentrate to remove pyridine (toluene is co-evaporated), add 30mL water to dissolve the reaction mixture, and sequentially extract with 5×40mL dichloromethane (the combined aqueous phase is concentrated and dried to recover unreacted mannitol), and the organic phase Na 2 SO 4 Drying, filtration, concentration, and silica gel column chromatography (V (petroleum ether): V (ethyl acetate) = 4:1 → 2:1 → ethyl acetate elution) gave 2.3 g of colorless syrupy 1-triphenyl Methylmannitol (62% yield from triphenylchloromethane).

[0026] 6.0g (0.25mol) of NaH, 50mL of anhydrous DMF, heated at 65°C, and added dropwise 29mL (0.25mol) of BnCl to the system while stirring, and simultaneously added dropwise 9.7g (23.0mmol) of 1- Trityl mann...

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Abstract

The invention provides a method for preparing 2, 3, 4, 5, 6-penta-O-benzyl mannose from D-mannitol. Firstly, the D-mannitol reacts with triphenylchloromethane to obtain 1-triphenylmethyl mannitol under the dissolution and catalysis of pyridine; secondly, the 1-triphenylmethyl mannitol performs a benzylation reaction with benzochloride to obtain 2, 3, 4, 5, 6-penta-O-benzyl-1-triphenylmethyl mannitol under the catalysis of NaH and the dissolution of DMF; and then CH2Cl2 and the 2, 3, 4, 5, 6-penta-O-benzyl-1-triphenylmethyl mannitol dissolved by MeOH react with BF3.Et2O to obtain 1, 2, 3, 4, 5-penta-O-phenyl mannitol, and finally the 1, 2, 3, 4, 5-penta-O-phenyl mannitol is oxidized by a Collins method to obtain the 2, 3, 4, 5, 6-penta-O-benzyl mannose. The invention provides new technical support for the preparation of the 2, 3, 4, 5, 6-penta-O-benzyl mannose; and the method has the advantages of cheap raw materials, easily obtained reagent, mild conditions, and simpler and more convenient operation, avoids the use of extremely toxic substances, and is easier for the realization of laboratories and industrialization.

Description

technical field [0001] The invention belongs to the synthesis method of 2,3,4,5,6-penta-O-benzyl mannose, especially relates to the preparation of 2,3,4 by taking D-mannitol as raw material through protection, deprotection and oxidation of hydroxyl , 5,6-Penta-O-benzylmannose method. Background technique [0002] As a chemically modified sweetener of sugars, sugar alcohols are firstly used as ingredients in low-calorie, low-sugar foods. It can also be used in many fields such as chemical industry, daily chemical industry, textile, leather, tobacco, and papermaking. As a natural product, D-mannitol widely exists in the roots, stems, leaves, etc. of plants in nature. It is the first crystalline sugar alcohol found in nature and the only one extracted from plants in nature. sugar alcohols of industrial value. Mannitol is an important fine chemical product, which can be used in medicine and additives, feed additives, plasticizers, textile auxiliary agents, surfactants, etc. It...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07H15/203C07H1/00
Inventor 方志杰程杰王立成王光辉蔡亚李松陈凯张振宇
Owner CHANGZHOU NIUTANG CHEM PLANT CO LTD