A method for preparing hydrogenated cardanol glycoside
By using Ca catalyst to catalyze the reaction of hydrogenated cashew glycosides with sugar compounds under mild conditions, the problems of low catalytic efficiency and environmental pollution in traditional methods have been solved, realizing the green and large-scale preparation of hydrogenated cashew glycosides and enhancing their industrial application potential.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING TECH UNIV
- Filing Date
- 2026-06-02
- Publication Date
- 2026-07-31
AI Technical Summary
Existing synthetic methods are difficult to synthesize hydrogenated cashew glycosides efficiently, especially in long-chain hydrophobic substrates where catalytic efficiency is low, reaction conditions are limited, and traditional catalysts pose environmental pollution risks, making it difficult to meet the needs of large-scale production.
Hydrogenated cashew glycosides were prepared by catalyzing the reaction of cashew phenol with sugar compounds under mild conditions using Ca catalyst, followed by dissolution in dichloromethane, washing with water, purification by column chromatography, and hydrolysis with sodium methoxide/methanol.
This method achieves a highly stereoselective glycosylation reaction under mild reaction conditions, avoiding the use of strong acids and toxic solvents, providing a green and large-scale preparation route, and enhancing the industrial application value of hydrogenated cashew glycosides.
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Figure CN122483117A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of organic chemical synthesis technology, and particularly relates to a method for preparing hydrogenated cashew glycosides. Background Technology
[0002] Cashew nut shell oil is a natural phenolic compound extracted from cashew nut shell oil. It boasts advantages such as wide availability, renewability, low cost, and environmental friendliness. Its molecular structure combines a rigid aromatic ring, reactive phenolic hydroxyl groups, and a long-chain flexible alkyl group, making it an ideal platform molecule in chemical engineering. However, the alkyl side chains of natural cashew nut shell oil contain multiple unsaturated double bonds, leading to problems such as easy oxidation and discoloration, poor weather resistance, and insufficient chemical stability in practical applications, limiting its use in high-end light-colored products and scenarios with stringent stability requirements. To overcome these shortcomings, hydrogenated cashew nut shell oil has emerged, its core value lying in combining the structural advantages of natural cashew nut shell oil with the performance improvements brought by hydrogenation modification. Structurally, hydrogenated cashew nut shell oil, through selective catalytic hydrogenation, retains the aromatic ring and phenolic hydroxyl groups while saturating the unsaturated double bonds in the alkyl side chains, forming a unique structure of "saturated flexible side chains and retained rigid aromatic rings." This structural feature endows it with multiple performance advantages: side chain saturation brings excellent antioxidant capacity, weather resistance, and light color (changing from dark brown to light yellow or even near colorless); the retention of the aromatic ring provides good rigidity, heat resistance, and chemical resistance; and the phenolic hydroxyl group retains suitable reactivity, allowing for subsequent chemical modifications such as glycosylation, esterification, and etherification. Based on these structural and performance characteristics, hydrogenated cashew nut shell phenol has been widely used in polymer materials, coatings and adhesives, surfactants, and synthetic resins, becoming a highly regarded platform molecule in green chemistry and functional materials research.
[0003] Glycosides are a class of natural or synthetic compounds formed by the condensation reaction of the hemiacetal hydroxyl group of a sugar with the hydroxyl, amino, or thiol group of another molecule (aglycone). They are widely found in plants, microorganisms, and animals, playing crucial roles in life processes such as cell recognition, signal transduction, and metabolic regulation. Their amphiphilic structure gives glycosides unique application value in the field of surfactants. Compared to traditional petroleum-based surfactants, glycoside surfactants have higher biodegradability, lower skin irritation, and better environmental compatibility, thus attracting widespread attention in areas such as daily detergents, personal care, food emulsification, and pesticide adjuvants. However, traditional glycoside synthesis methods typically rely on strong Lewis acid catalysts or high-temperature conditions, resulting in poor reaction selectivity and products that are often mixtures of α / β isomers. Furthermore, they are difficult to apply to acid- or heat-sensitive substrates, which greatly limits the application of glycosides in complex biological systems.
[0004] Cashew glycosides, as a class of amphiphilic compounds possessing both the lipophilic long chains of cashew phenol and the hydrophilicity of sugar units, have broad application prospects in fields such as green surfactants, functional polymer materials, and drug delivery systems. However, existing synthetic methods have significant limitations. Although enzymatic glycosylation methods offer mild reaction conditions and high selectivity, they suffer from problems such as expensive sugar donors, poor enzyme stability, and limited substrate universality, making it difficult to meet the needs of large-scale production. Especially in the hydrogenation of cashew phenol and other substrates with long-chain hydrophobic structures, the catalytic efficiency of enzymes often decreases significantly, resulting in low reaction conversion rates and long reaction times, further limiting their industrial application value. To address these issues, this invention proposes a novel hydrogenated cashew glycoside synthesis method catalyzed by a Ca catalyst. As a mild and efficient Lewis acid catalyst, the Ca catalyst can achieve highly stereoselective glycosylation reactions under mild reaction conditions, avoiding the use of highly corrosive acids and toxic solvents. This method not only solves the technical problems of low catalytic efficiency and limited reaction conditions in long-chain hydrophobic substrates by enzymatic methods, but also provides a feasible route for the green and large-scale preparation of hydrogenated cashew glycosides, which has important industrial application value and environmental significance. Summary of the Invention
[0005] To overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for preparing hydrogenated cashew glycoside.
[0006] This invention is achieved by a method for preparing cashew glycoside (hydrogenated cashew glycoside), the method comprising the following steps:
[0007] (1) Cashew nut phenol (hydrogenated cashew nut phenol), carbohydrate compounds and Ca catalyst were sequentially added to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain a reaction solution. The chemical structural formula of the cashew nut phenol (hydrogenated cashew nut phenol) is shown below:
[0008]
[0009] The chemical structural formula of the carbohydrate compound is shown below:
[0010]
[0011] (2) Add water to the reaction solvent in the reaction solution, separate the liquid and wash the organic phase three times with water. Collect the organic phase, dry it with anhydrous sodium sulfate, and then purify it by column chromatography to obtain the cashew glycoside intermediate (hydrogenated cashew glycoside);
[0012] The chemical structural formula of the cashew glycoside intermediate (hydrogenated cashew glycoside) is shown below:
[0013]
[0014] (3) The obtained cashew glycoside intermediate was dissolved in dichloromethane, and sodium methoxide / methanol solution was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the cashew glycoside was purified by column chromatography.
[0015] The chemical structural formula of the cashew glycoside (hydrogenated cashew glycoside) is shown below:
[0016]
[0017] Among them, R 1 Selected from C n H 2n+1 C n H 2n-1 C n H 2n-3 C n H 2n-5 Any one of them;
[0018] R 2 It is selected from either acetyl or benzyl.
[0019] Preferably, in step (1), the Ca catalyst is selected from any one of Ca(NTf2)2, Ca(OTf)2, and CaF2.
[0020] Preferably, in step (1), the molar volume ratio of cashew phenol (hydrogenated cashew phenol), carbohydrate compound, Ca catalyst and reaction solvent is (1-1.2) mmol: (1-2) mmol: (0.01-0.05) mmol: (10-20) mL.
[0021] Preferably, in step (2), the purified developing solvent system is petroleum ether / ethyl acetate = 15:1.
[0022] Preferably, in step (3), the molar volume ratio of cashew glycoside intermediate, sodium methoxide / methanol solution and reaction solvent is (1) mmol: (10-18) mmol: (10-20) mL.
[0023] Preferably, in step (3), the purified developing solvent system is dichloromethane / methanol = 1:2.
[0024] This invention overcomes the shortcomings of existing technologies and provides a method for preparing hydrogenated cashew glycosides. This invention directly uses cashew phenol (hydrogenated cashew phenol) and carbohydrate compounds as raw materials, employs a Ca catalyst, and stirs in dichloromethane at room temperature for 36 hours. The cashew phenol (hydrogenated cashew phenol) glycoside intermediate is purified by column chromatography, dissolved again in dichloromethane, and then hydrolyzed with sodium methoxide / methanol solution to finally obtain the cashew phenol (hydrogenated cashew phenol) glycoside product. The reaction process is as follows:
[0025]
[0026] Compared with the shortcomings and deficiencies of existing technologies, the present invention has the following beneficial effects:
[0027] (1) The hydrogenated cashew phenol used in the preparation method of this invention is derived from cashew shell liquid, which is an agricultural processing by-product. It has the characteristics of readily available raw materials, renewability, and low cost. Sugar compounds are inexpensive, have good stability, and are easy to store and use. Both are green and renewable resources, which are in line with the concept of green chemistry development.
[0028] (2) The entire reaction of this invention is carried out at room temperature, without the need for heating or high pressure, making it convenient and environmentally friendly. Using a Ca-containing catalyst, only the catalytic equivalent is required to efficiently promote glycosidic bond formation, avoiding the use of expensive or highly toxic metal catalysts. The reaction is simple to operate and does not require pre-protection of the phenolic hydroxyl groups of cashew phenol (hydrogenated cashew phenol), making it convenient and environmentally friendly. Attached Figure Description
[0029] Figure 1 This is the 1H NMR spectrum of the compound hydrogenated cashew glycoside in Example 1 of this invention;
[0030] Figure 2 This is the carbon NMR spectrum of the compound hydrogenated cashew glycoside in Example 1 of this invention;
[0031] Figure 3 This is the infrared spectrum of the compound hydrogenated cashew glycoside in Example 1 of the present invention; Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0033] Example 1
[0034] (1) Hydrogenated cashew phenol, β-D-glucose pentaacetate, and Ca(NTf2)2 were added sequentially to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain the reaction solution. The reaction equation is as follows:
[0035]
[0036] (2) After the reaction was complete as monitored by TLC, water was added to the reaction solution, and the mixture was separated. The organic phase was washed three times with water. The organic phase was collected, dried over anhydrous sodium sulfate, and dichloromethane was removed by a vacuum rotary evaporator. The product was separated by column chromatography using a petroleum ether / ethyl acetate system (15:1) as the eluent. The product was a white solid compound, hydrogenated cashew glycoside intermediate, with a yield of 78%.
[0037] (3) The hydrogenated cashew glycoside intermediate was dissolved in dichloromethane, and a sodium methoxide / methanol solution (18 equivalents) was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the product was separated by column chromatography using a dichloromethane / methanol system (1:2) as the eluent. The product was a white solid compound, hydrogenated cashew glycoside, with a yield of 92%. The reaction equation is as follows:
[0038]
[0039] Example 2
[0040] (1) Hydrogenated cashew phenol, β-D-glucose pentaacetate, and Ca(OTf)₂ were sequentially added to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain the reaction solution. The reaction equation is as follows:
[0041]
[0042] (2) After the reaction was complete as monitored by TLC, the reaction solvent in the reaction solution was added to water, and the mixture was separated. The organic phase was washed three times with water. The organic phase was collected, dried over anhydrous sodium sulfate, and dichloromethane was removed by vacuum rotary evaporator. The product was separated by column chromatography using a petroleum ether / ethyl acetate system (15:1) as the eluent. The product was a white solid compound, hydrogenated cashew glycoside intermediate, with a yield of 70%.
[0043] (3) The intermediate of hydrogenated cashew phenol glucoside was dissolved in dichloromethane, and a sodium methoxide / methanol solution (18 equivalents) was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the product was separated by column chromatography using a dichloromethane / methanol system (1:2) as the eluent. The product was a white solid compound, hydrogenated cashew phenol glucoside, with a yield of 90%. The reaction equation is as follows:
[0044]
[0045] The compound hydrogenated cashew glycoside was characterized, and the results are as follows: Figures 1-3 As shown, Figure 1 It is the 1H NMR spectrum of hydrogenated cashew glycoside; Figure 2 It is the carbon NMR spectrum of hydrogenated cashew glycoside; Figure 3 This is the infrared spectrum of hydrogenated cashew glycoside.
[0046] Example 3
[0047] (1) Cashew phenol, β-D-glucose pentaacetate and Ca(NTf2)2 were added sequentially to a dry 100mL reaction flask, and dichloromethane was added to dissolve them completely. The mixture was stirred at room temperature for 36 hours to obtain the reaction solution. The reaction equation is as follows:
[0048]
[0049] (2) After the reaction was complete as monitored by TLC, the reaction solvent in the reaction solution was added to water, and the mixture was separated. The organic phase was washed three times with water. The organic phase was collected, dried over anhydrous sodium sulfate, and dichloromethane was removed by vacuum rotary evaporator. The product was separated by column chromatography using a petroleum ether / ethyl acetate system (15:1) as the eluent. The product was a white solid compound, cashew nut glucoside intermediate, with a yield of 68%.
[0050] (3) The cashew glycoside intermediate was dissolved in dichloromethane, and a sodium methoxide / methanol solution (18 equivalents) was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the product was separated by column chromatography using a dichloromethane / methanol system (1:2) as the eluent. The product was a white solid compound, cashew glycoside, with a yield of 94%. The reaction equation is as follows:
[0051]
[0052] Example 4
[0053] (1) Hydrogenated cashew phenol, β-L-glucose pentaacetate, and Ca(NTf2)2 were added sequentially to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain the reaction solution. The reaction equation is as follows:
[0054]
[0055] (2) After the reaction was complete as monitored by TLC, water was added to the reaction solution, and the mixture was separated. The organic phase was washed three times with water. The organic phase was collected, dried over anhydrous sodium sulfate, and dichloromethane was removed by a vacuum rotary evaporator. The product was separated by column chromatography using a petroleum ether / ethyl acetate system (15:1) as the eluent. The product was a white solid compound, hydrogenated cashew nut glucoside intermediate, with a yield of 71%.
[0056] (3) The hydrogenated cashew glycoside intermediate was dissolved in dichloromethane, and a sodium methoxide / methanol solution (18 equivalents) was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the product was separated by column chromatography using a dichloromethane / methanol system (1:2) as the eluent. The product was a white solid compound, hydrogenated cashew glycoside, with a yield of 87%. The reaction equation is as follows:
[0057]
[0058] Example 5
[0059] (1) Hydrogenated cashew phenol, 1,2,3,4-tetra-O-acetyl-β-D-xylanose and Ca(NTf2)2 were added sequentially to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain the reaction solution. The reaction equation is as follows:
[0060]
[0061] (2) After the reaction was complete as monitored by TLC, water was added to the reaction solution, and the mixture was separated. The organic phase was washed three times with water. The organic phase was collected, dried over anhydrous sodium sulfate, and dichloromethane was removed by a vacuum rotary evaporator. The product was separated by column chromatography using a petroleum ether / ethyl acetate system (15:1) as the eluent. The product was a white solid compound, hydrogenated cashew glycoside intermediate, with a yield of 73%.
[0062] (3) The intermediate of hydrogenated cashew phenol xylose was dissolved in dichloromethane, and a sodium methoxide / methanol solution (18 equivalents) was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the product was separated by column chromatography using a dichloromethane / methanol system (1:2) as the eluent. The product was a white solid compound, hydrogenated cashew phenol xylose, with a yield of 92%. The reaction equation is as follows:
[0063]
[0064] Examples 6-10
[0065] Examples 6-10 are basically the same as Example 1 above, and the products obtained are the same. The differences are shown in Table 1 below:
[0066] Table 1 Comparison of Implementation Differences
[0067] Example 6 methanol <![CDATA[Ca(NTf2)2]]> 65％ Example 7 Acetonitrile <![CDATA[Ca(NTf2)2]]> 57％ Example 8 dichloromethane <![CDATA[CaF2]]> 42％ Example 9 methanol <![CDATA[Ca(OTf)2]]> 60％ Example 10 Acetonitrile <![CDATA[Ca(OTf)2]]> 55％
[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing hydrogenated cashew glycosides, characterized in that, The method includes the following steps: (1) Cashew nut phenol (hydrogenated cashew nut phenol), carbohydrate compounds and Ca catalyst were sequentially added to a dry 100 mL reaction flask, and dichloromethane was added to completely dissolve them. The mixture was stirred at room temperature for 36 hours to obtain a reaction solution. The chemical structural formula of the cashew nut phenol (hydrogenated cashew nut phenol) is shown below: The chemical structural formula of the carbohydrate compound is shown below: (2) Add water to the reaction solvent in the reaction solution, separate the liquid and wash the organic phase three times with water. Collect the organic phase, dry it with anhydrous sodium sulfate, and then purify it by column chromatography to obtain the cashew glycoside intermediate (hydrogenated cashew glycoside); The chemical structural formula of the cashew glycoside intermediate (hydrogenated cashew glycoside) is shown below: (3) The obtained cashew glycoside intermediate was dissolved in dichloromethane, and sodium methoxide / methanol solution was added with stirring. After the addition, the reaction solution changed from clear to turbid and a white solid precipitated. The mixture was stirred overnight. The volatile solvent was removed by concentration, and the cashew glycoside was purified by column chromatography. The chemical structural formula of the cashew glycoside (hydrogenated cashew glycoside) is shown below: Among them, R 1 Selected from C n H 2n+1 C n H 2n-1 C n H 2n-3 C n H 2n-5 Any one of them; R 2 It is selected from either acetyl or benzyl.
2. The method as described in claim 1, characterized in that, In step (1), the Ca catalyst is selected from any one of Ca(NTf2)2, Ca(OTf)2, and CaF2.
3. The method as described in claim 1, characterized in that, In step (1), the molar volume ratio of cashew phenol (hydrogenated cashew phenol), sugar compound, Ca catalyst and reaction solvent is (1-1.2) mmol: (1-2) mmol: (0.01-0.05) mmol: (10-20) mL.
4. The method according to claim 1, wherein in step (2), the purified developing solvent system is petroleum ether / ethyl acetate = 15:
1.
5. The method as described in claim 1, characterized in that, In step (3), the molar volume ratio of cashew glycoside intermediate, sodium methoxide / methanol solution and reaction solvent is (1) mmol: (10-18) mmol: (10-20) mL.
6. The method as described in claim 1, characterized in that, In step (3), the purified developing solvent system is dichloromethane / methanol = 1:2.