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Synthesis method of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one

A synthetic method, the technology of dihydroxy, which is applied in the direction of organic chemistry, etc., can solve the problems of difficult preparation and purification, low yield, etc.

Active Publication Date: 2020-01-21
CHINA TOBACCO HENAN IND
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of this invention is to provide a kind of synthetic method of 2,3-dihydro-3,5-dihydroxyl-6-methyl-4H-pyran-4-one, to solve the prior art synthetic 2,3-dihydroxy Low yield of hydrogen-3,5-dihydroxy-6-methyl-4H-pyran-4-one and difficult preparation and purification

Method used

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  • Synthesis method of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one

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Experimental program
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Effect test

Embodiment 1

[0040] Preparation of maltol acetate: In a 100mL round bottom flask, add 5.04g maltol (40mmol), 3.93g acetyl chloride (50mmol) and 50mL absolute ethanol, react at 80°C for 4h, cool to room temperature after the reaction, Evaporate the solvent under reduced pressure at 25°C and 20 Pa, add 30 mL of distilled water, extract with dichloromethane for 3 times, combine the organic phases, and successively wash with saturated NaHCO 3 solution combined with saturated NaCl solution and washed 3 times, anhydrous NaCl 2 SO 4 After drying, the solvent was distilled off under reduced pressure to obtain 6.40 g of white solid, maltol acetate, with a yield of 95.24%.

[0041] Preparation of dihydromaltol acetate: In a 100 mL round bottom flask, add 3.36 g of maltol acetate (20 mmol), 50 mL of ethyl acetate and 0.5 g of Pd / C, replace the round bottom flask with nitrogen 3 times , replaced with hydrogen 3 times, and reacted for 6 hours at 2 times atmospheric pressure. During the period, the pr...

Embodiment 2

[0046] Preparation of maltol acetate: In a 100mL round bottom flask, add 5.04g maltol (40mmol), 4.71g acetyl chloride (60mmol) and 50mL absolute ethanol, react at 100°C for 6h, cool to room temperature after the reaction, Evaporate the solvent under reduced pressure at 50°C and 75Pa, add 40 mL of distilled water, extract 3 times with dichloromethane, combine the organic phases, and successively wash with saturated NaHCO 3 solution combined with saturated NaCl solution and washed 3 times, anhydrous NaCl 2 SO 4 After drying, the solvent was distilled off under reduced pressure at 50° C. and 75 Pa to obtain 6.52 g of white solid, maltol acetate, with a yield of 97.02%.

[0047] Preparation of dihydromaltol acetate: In a 100 mL round bottom flask, add 3.36 g of maltol acetate (20 mmol), 50 mL of ethyl acetate and 0.6 g of Pd / C, replace the round bottom flask with nitrogen 3 times , replaced with hydrogen 3 times, and reacted at 2 times atmospheric pressure for 8 hours. During th...

Embodiment 3

[0052] Preparation of maltol acetate: In a 100mL round bottom flask, add 5.04g maltol (40mmol), 5.10g acetic anhydride (50mmol) and 50mL absolute ethanol, react at 85°C for 6h, cool to room temperature after the reaction, Evaporate the solvent under reduced pressure at 30°C and 50Pa, add 30mL of distilled water, extract with dichloromethane for 3 times, combine the organic phases, and successively wash with saturated NaHCO 3 solution combined with saturated NaCl solution and washed 3 times, anhydrous NaCl 2 SO 4 After drying, the solvent was distilled off under reduced pressure to obtain 6.14 g of white solid, maltol acetate, with a yield of 91.37%.

[0053] Preparation of dihydromaltol acetate: In a 100mL round bottom flask, add 3.36g maltol acetate (20mmol), 50mL ethyl acetate and 0.35g nickel, replace the round bottom flask with nitrogen 3 times, hydrogen Replaced 3 times, reacted at 2 times atmospheric pressure for 8 hours, during which the pressure of the round bottom f...

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Abstract

The invention relates to a synthesis method of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, which creatively uses maltose as an initial raw material to synthesize the 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one. The synthesis method comprises: firstly, generating maltol acetate through acetylation; secondly, carrying out catalytic hydrogenation to obtain dihydromaltol acetate; adding asilylation reagent again to synthesize a dihydromaltol acetate silyl enol ether compound; increasing reaction activity of 5-position methylene and introducing hydroxy to the 5-position through peroxidation to obtain 5-hydroxy-dihydromaltol acetate; and performing a deacetylation reaction to obtain the 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one that is a target compound. According to the technical scheme, the five-step reaction process is simple, the yield is higher than 80%, the purity of the final product reaches 98% or above, large-scale production can be conducted, and the method has a wide application prospect.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and specifically refers to a synthesis method of 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one. Background technique [0002] 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one is commonly found in cigarette smoke, Maillard reaction products, sugar cleavage products and natural extracts. [0003] Structurally, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one belongs to pyrone enol ketone compounds, which have cyclic enol ketones Most of the compounds have caramel-like aroma; compared with maltol and other caramel-like aroma substances, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one has more Good water solubility, the "sweetness" in the taste is more prominent; it has a significant positive correlation with the "sweetness" of smoke, which can significantly improve the sweetness of cigarette smoke, highlighting the "sweetness" and "moistness" of cigarettes taste characteristics. ...

Claims

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Application Information

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IPC IPC(8): C07D309/32
CPCC07D309/32
Inventor 陈芝飞蔡莉莉王保会赵志伟许克静白冰何文婕席高磊刘强
Owner CHINA TOBACCO HENAN IND
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