WO2001092341A1

WO2001092341A1 - Hexaglucal compound and the use and the methods of preparing them

Info

Publication number: WO2001092341A1
Application number: PCT/CN2001/000619
Authority: WO
Inventors: Zhong Wu
Original assignee: Zhong Wu
Priority date: 2000-04-28
Filing date: 2001-04-27
Publication date: 2001-12-06
Also published as: AU2001268903A1; CN1108296C; WO2001092341A8; CN1269361A

Abstract

This invention provides an hexaglucal compounds of formula (III), which is a new kind of bio-pesticide. And also provides the processes for preparing them, which include the regioselective reaction of compounds presented by formula (I) and (II) as reactants, wherein L is leaving group. This invention also discloses the hexaglucal compound used in prevention and cure of plant diseases and insect pests, and useful as crop preservation agent.

Description

Polydextrose compound, its synthesis method and application

The invention relates to the field of biological pesticides, in particular to the structure and chemical synthesis method of a novel biological pesticide compound, a glucomannose compound, and also relates to the application of the compound in controlling plant diseases and insect pests and storing and keeping freshness of crops. Background of the invention

For a long time, the use of pesticides and preservatives has played an important role in increasing agricultural production and keeping crops fresh. The research and development of new pesticides and preservatives have never stopped. To this day, a large number of chemical products have been gathered on the market. However, the use of chemical pesticides by humans for decades has caused the consolidation of large areas of land, resulting in the loss of nutrients in the land and serious environmental pollution. Some toxic pesticides have entered the human body through the food chain, producing rich in human blood and bones. It is even more surprising that even in polar regions where humans rarely get involved, organophosphorus toxic pesticides have been found. In addition, people have raised doubts about the use of a variety of chemical preservatives. It is shown that these "preservatives" pose a more direct threat to humans, and all evidence has promoted the research and development of green pesticides and preservatives in countries around the world.

Several articles published by Albersheim and other scholars in the Journal of Biological Chemistry in 1984 opened up new ideas for the development of green pesticides. (See Sharp.JK; Valent.B .; Albersheim.PJ Biol. Chem (1984, Vol. 259, 11312-11341) He subsequently proposed "oligosaccharins" as a general term for this new class of compounds. (See Albersheim.P. "Oligosaccharins", Scientific American Vol. 253 (3), September, 1985). According to the results of Albersheim's research, plants themselves can produce compounds that resist the attack of foreign pathogens, that is, when the oligosaccharides in the plant are in an activated state, it can mobilize the plant to produce some volatile, killing compounds through the transmission of certain information. Compounds of dead pathogens, these oligosaccharides are usually part of the plant cell wall, when the pathogens invade the plants, An enzyme released by these pathogens can activate more oligosaccharides in the plant cell wall, and these highly specific oligosaccharides can be recognized by plants and stimulate plant tissues to synthesize more antibiotics, so they accumulate at the infected site A large number of phytoalexins that can kill pathogenic bacteria.

According to the above research results, it can be inferred that the degradation of plant cell walls with special enzymes is a method to obtain these oligosaccharides, but because of its extremely low content, it cannot form industrial production. Therefore, some people have suggested that enzymes be used to stimulate plants to produce Disease-resistant phytoalexins, but not practical due to the slow process.

It is said that the glucohexaose obtained from the degradation of natural dextran has a preventive effect on rice pests and diseases. The structure and synthesis of these related glucohexaose compounds have also been reported. See Yamada.H; Harada .; Takahashi.T., J. Am. Chem. Soc. 1994, 116, 7919-7920, and references cited therein. The glucan compound is a representative of the oligosaccharides, and is also a type of polysaccharides that are most known among oligosaccharides. It can be said that as a new type of biological pesticide, it will show a wide range of application advantages. Summary of invention

The present invention provides a dextran compound, which is one of the dextran compounds. It is a hexasaccharide compound with a brand-new chemical structure, and can be used as a non-toxic biological pesticide to control plant diseases and insect pests. And the preservation of agricultural products.

Another aspect of the present invention is to provide a method for chemically synthesizing the aforementioned glucomannose compound, which comprises selecting or preparing an appropriate trisaccharide donor and a trisaccharide acceptor compound as reactants, using a Lewis acid as a catalyst, The process of regioselective coupling synthesis in a solvent.

The present invention also proposes the use of the aforementioned glucopolyene compound in promoting plant growth, controlling pests and diseases, and storing and keeping freshness of crops. Detailed description of the invention

The dextran compound provided by the present invention has a chemical structure represented by the following formula (II):

According to the purpose of the present invention, a method for synthesizing a glucovinose compound is also provided. The process includes a regioselective coupling synthesis reaction using a compound of structural formulae (I) and (II) as a reactant. The reaction conditions include ： Lewis acid as catalyst, in aprotic organic solvent, the reaction temperature is below 4 ° C and 4 ° C:

Where: L is a leaving group, which represents a halogen such as fluorine, chlorine, bromine, and iodine; L may also be an ester group

0 0

Such as trifluoroacetate (-O CF ₃ ), trichloroacetate (-ο6α ₃ ), trichloroacetimide

0

(-0C (NH) CC1 ₃ ) or a phosphate ester derivative of structure -0 OZ) ₂ , where Z is benzyl, ethyl or fluorenyl; the leaving group L may also be 1-enoxy , Especially n-pentenyloxy.

In the above reaction, RR ² and R ⁵ are any same or different acyl or acyl derivatives, such as acetyl (_Ac), benzoyl (-Bz), etc .; R ³ is hydrogen, acyl or acyl derivative, when When R ³ is not hydrogen, it may be the same as RR ² and / or R ⁵ . -The completion of the above reaction can be detected by thin layer chromatography (TLC) in an ethyl acetate-petroleum ether system, and the solvent ratio can be 1: 4 ~ 2: 1. This detection method is a conventional detection method in the art. Generally The technicians can find the appropriate conditions for the synthesis operation based on the detection process, such as the reaction material ratio, the amount of catalyst and the determination of the reaction time.

According to the method of the present invention, the molar ratio of reactants (I) and (II) is usually 0.5: 1 to 2: 1. The Lewis acid catalyst used is selected from silver salts such as trifluorophosphonium sulfonate (AgOTf), divalent mercury salts such as mercury cyanide (Hg (CN) ₂ ), trimethylsilyl trifluorophosphonium sulfonate (TMSOTf) , Triethylsilyl trifluorophosphonium sulfonate (TESOTf), N-iodosuccinimide (NIS), boron trifluoride ether (BF ₃ · Et ₂ 0) or mixtures thereof, etc. Different groups L, the choice of catalyst, and the determination of the amount of catalyst added should be aimed at the completion of the reaction, which is easily done by those skilled in the art without the need to spend creative labor. The addition amount of the Lewis acid of the present invention may generally be 0.1 to 2 equivalents per mol of the reactant.

The aprotic organic solvent of the present invention may include dichloroalkane (such as dichloromethane, 1,2-dichloroethane), acetonitrile (CH ₃ CN), dimethylformamide, diethyl ether, benzene, toluene, or a mixture thereof Solvents, etc.

In the present invention, a regioselective coupling method using n-pentenyloxy as a leaving group is preferred.

In the synthesis method provided by the present invention, the reactants (I) and (II) are a trisaccharide donor compound and a trisaccharide acceptor compound, respectively, starting from the appropriate monosaccharide compound such as D-glucose or D-glucoside through the corresponding sugar This can be obtained during the basicization reaction. For example, Ferrier.RJ. By Carbohydr. Res. 1973, 27, P 55; Roth, W .; Pigman, W. By Methods Carbohydr Chem. 2 (1963), 405; Kitagawa, I .; Shibuya, H. Etal., Chem. Pham. Bull, 1989, 37, P1131-1133; and Fraser-Reid, B .; Udodong, UE, Synlett, 1992, P927.

, And the present invention is hereby incorporated by reference.

The preferred technical solution of the present invention further includes the following process for preparing compound (I), UI): (1) Using D-glucose as the raw material, first prepare compounds 4, 4b, 5 and 2, respectively, where: L is the aforementioned leaving group, or can be changed to the leaving group by appropriate modification, κ R ² The definitions of R ³ , R ³ and R ⁵ are the same as above, and T and P are also detachable groups, for example, thiophenyl (-SPh), trichloroacetimide ester group, and the protective group R ⁴ in compound 2 May be acyl, preferably acetyl

(-Ac), benzoyl (-Bz), benzyl or its derivative, triphenylfluorenyl or its derivative such as tert-butyltritylsilyl (-TBDPS), alkylsilicon such as tert-butyl Difluorene-based silicon (TBS), etc .;

(2) Compounds 4 and 5 are prepared by using a Lewis acid as a catalyst in an anhydrous organic solvent, and a glycosylation reaction is carried out in a nitrogen atmosphere below 0 ° C, followed by a common acylation reaction to prepare a trisaccharide donor compound (I) Wherein the amount of the Lewis acid catalyst used is 0.1 to 0.5 equivalents of the Lewis acid per equivalent of the compound 4;

(3) The compound 2 and D-glucomannose 3 prepared in the process (1) are prepared by using a Lewis acid as a catalyst in an anhydrous organic solvent and a glycosylation reaction under a nitrogen atmosphere at a temperature below 0 ° C to prepare a disaccharide compound 6 Wherein, the amount of the Lewis acid catalyst used is 3 to 5 equivalents of the Lewis acid per equivalent of the compound 2;

(4) The disaccharide Compound 6 Compound 4b to below 0 ° C in the glycosylation reaction in a nitrogen atmosphere, to give the trisaccharide compound (Ila) removing the protecting group R ⁴ become trisaccharide acceptor compound (II), In the glycosylation reaction, the Lewis acid catalyst is used in an amount of 0.1 to 1 equivalent of Lewis acid per equivalent of compound 4b.

According to the preferred solution of the present invention, the realization of the process can be expressed as follows:

For the process of synthesizing compound 2, 4, 4b, 5 from the commercially available product D-glucose 1 in the above process, refer to the cited documents above. D-glucal compound 3 is a commercially available product, and it can also be prepared from the initial stage. The raw material D-glucose 1 was synthesized.

The target compound (111) can be obtained by synthesizing the donor compound and the acceptor compound prepared in the above steps according to the method of the present invention. The Lewis acids and organic solvents involved in the above steps are all the substances and specific compounds mentioned above.

According to the present invention, the synthesis process further comprises reacting the reactants (I) and (II) to obtain an intermediate product (Ilia), and the intermediate product is then deprotected to prepare a final reaction product (IΠ),

Ilia

As a conventional technology in the field of organic synthesis, the synthesis of some intermediate products in the synthesis method of the present invention may include a purification process as required. The main methods used include silica gel column separation, reduced pressure concentration, and recrystallization. The operating conditions and steps are all It is conventional and does not fall within the protection scope of the present invention, so it will not be described in detail. The ratio between the reactants and the amount of catalyst used are not technically critical for the formation of intermediate products in each step. After providing a synthetic path, those skilled in the art can easily implement it.

The glucomannose product synthesized by the present invention provides a novel structure of a biological pesticide compound. It has been proved by experiments that it is good in controlling plant and crop diseases and insect pests caused by fungi, and in the storage and preservation of crops, fruit and vegetable products. effect. The dextran product of the present invention can be used directly, and is generally formulated as an aqueous solution with a molar concentration of ιο- ^{8 to} ιο- ⁶ grade, sprayed on plants infected with pests or diseases, or sprayed on fruit and vegetable products that need to be stored fresh. It has the advantages of convenient use, safety and non-toxicity, and as a biological pesticide, long-term use will not cause resistance to bacteria. Embodiments of the invention

The following describes the present invention in detail through specific embodiments, so that those skilled in the art can better understand the technical solutions and features of the present invention, but do not limit the scope of the present invention. Example 1

(1) 30 grams of pentaacetylated D-glucoside la '(commercially available product or conventional method from D- Prepared from glucose) Dissolved in 150 ml of tetrahydrofuran-methanol (THF-MeOH) mixed solution (proportion is 7: 3), pass in NH ₃ gas at 0 ° C for 10 minutes, and seal and stir at room temperature until the raw materials completely disappear. The reaction progress was detected by TLC), and the product was distilled under reduced pressure. The product was purified by silica gel column chromatography to obtain a crystalline product. The mp was determined to be 112 ~ 114 ° C, and the yield was 80%.

Take 20 g of the above product and dissolve it in 200 ml of anhydrous dichloromethane, add 10 ml of trichloroacetonitrile and 30 g of anhydrous potassium carbonate, stir at room temperature overnight, and then remove the insoluble salt by filtration. Take the dichloromethane phase and concentrate it under reduced pressure. It was separated on a silica gel column to obtain a pure slurry with the structural formula 4a. The yield was 71%.

The above process was repeated with pentaphenylacylated D-glucoside lb ', and compound 4b was obtained with a yield of 65%, m.p. 89 ~ 90 ° C of the intermediate crystalline product.

(2) 15 g of chemically pure anhydrous D-glucose la, and 200 mg of camphor sulfonic acid are added to 120 ml of 4-pentenol at room temperature. The mixed system is heated in an oil bath to 90 ~ 100 ° C with a reaction of 16 Hours, the excess 4-pentenol was distilled off under reduced pressure, 0.5 ml of triethylamine was added, and the mixture was loaded on a silica gel column and rinsed with pure ethyl acetate to collect 19.6 g of 1-pentenyloxy at the 1-position. Compound (a) of group (-Opentenyl), yield 95%.

(3) 2 equivalents of compound 4a and 1 mole of compound 5a are dried under vacuum, and then mixed in an organic solvent of 1: 1 anhydrous acetonitrile and diamidinofluoramide (DMF), and mixed in a water bath Add 0.25 equivalent of trimethylsilyl trifluoromethanesulfonate (TMSOTf) dropwise under a nitrogen atmosphere, and then stir at room temperature for 4 hours. Add 5 ml of pyridine and 3 ml of acetic anhydride in order, and continue stirring at room temperature for 6 hours. Ordinary silica gel column chromatography gave trisaccharide donor compound 7b in a yield of 51%.

(4) Dissolve 1 equivalent of dry compounds 2a and 3 (both commercially available) in a 3: 1 organic solvent of anhydrous acetonitrile and diamidinofluoramide (DMF) at 0 ° C or ice Add 3 equivalents of N-iodosuccinimide (NIS) and 0.5 equivalents of trifluoromethanesulfonic acid (TfOH) catalyst in a water bath and under a nitrogen atmosphere, and stir at room temperature for 3 hours. Column separation gave disaccharide compound 6a in 78% yield.

(5) Dissolve 1 mole of the above-mentioned disaccharide compound 6a and 1.1 equivalents of the dried compound 4b in 20 ml of anhydrous dichloromethane, add 0.25 dropwise in an ice-water bath and under a nitrogen atmosphere. T CN01 / 00619 equivalent of trimethylsilyltrifluorophosphonium sulfonate (TMSOTf), and continue to stir at this temperature for 2 hours, and then add about 0.1ml of triethylamine to neutralize, and then concentrate on an ordinary silica gel column to separate. Compound 8a was obtained in a yield of 83%.

(6) 1 mole of compound 8a is dissolved in 10 ml of anhydrous dichloromethane, 3 ml of anhydrous methanol and about 1 ml of acetyl chloride are sequentially added, and after stirring at room temperature for 16 hours, triethylamine is added dropwise to neutralize to neutrality. Compound 8b, which is a trisaccharide acceptor compound, was isolated on an ordinary silica gel column with a yield of 70%.

(7) The dried compounds 7b and 8b are mixed in anhydrous dichloromethane at a molar ratio of 1.05: 1, and 0. Add 2 equivalents of N-iodosuccinimide (NIS) and 1 equivalent of triethylsilyltrifluorosulfonate under the protection of argon, continue stirring at this temperature for 5 hours, and add triethylamine to neutralize to Weakly acidic or neutral, to give glucovinose 9a.

(8) Dissolve 1 mole of compound 9a in 10 ml of methanol, add 1 ml of a 1N sodium hydroxide solution, and stir for 2 hours. During this period, maintain the pH at about 10.5, and then neutralize and remove salts with Dowex-50 (H ⁺ ) resin. Evaporate to dryness to obtain the final product, glucomannose compound 9b.

After detection, the ESI-Tof data of the compound 9b was 979, (M + Na ⁺ ).

The ¹ HNR data of this compound are: 6.40ppm (H-1 ¹ ), 4.89ppm (H-2 ¹ ), 4.70ppm (Hl ³ ' ⁶ ), 4.56ppm, 4.51ppm, 4,50ppm (3 d 7.9Hz H -1 ² ' ⁴ ' ⁵ ).

The product can be used directly as a biological pesticide.

The reactions described in this embodiment can be expressed as follows:

61900 / I0 3 / X3d

Example 2

1 mol of compound 2a in Example 1 was dissolved in 20 ml of anhydrous methanol, 0.5N sodium alcohol was added dropwise to pH 9-10, and the mixture was stirred at room temperature for 4 hours. The solution was neutralized with Dowex 50 (H +), and the salts were evaporated to dryness to obtain the compound. 2b, yield 95%.

This compound 2b was dissolved in 10 ml of pyridine in 1 mole, and 1.5 equivalents of triphenylfluorenyl chloride was added, and the mixture was stirred at 30 ° C overnight. Then, 1 ml of benzoyl chloride was added dropwise to the reaction system, and the mixture was stirred at room temperature for 6 hours. It was separated on a silica gel column to obtain compound 2c with a yield of 73%.

This product was used to replace 2a in (4) of Example 1 and react with compound 3 to prepare compound 6c with a yield of 78.1%.

Substitute compound 6c for 6a, and synthesize 8c with compound 4b as described in Example 1, wherein R ⁴ is triphenylfluorenyl (-Tr); for compound 8c, follow the process of obtaining 8b from 8a in Example 1 to make R ⁴ Deprotect the group to obtain the trisaccharide acceptor 8d, which was mixed with 7b in Example 1 in a benzene-xylene mixed solvent at a molar ratio of 0.95: 1, and 2 equivalents (NIS) was added at 0 ° C under argon protection. And 1 equivalent of triethylsilyltrifluorophosphonium sulfonate, the same steps (7) and (8) as in Example 1, to prepare the final product 9b, yield 63%.

The synthesis process is as follows:

619

Example 3

1 mol of the compound 2b prepared in Example 2 was dissolved in 10 ml of pyridine, 1.25 equivalents of t-butyldiphenylchlorosilane was added, and the mixture was stirred at room temperature overnight. Then, 1 ml of benzoyl chloride was added dropwise to the reaction system, and the mixture was stirred at room temperature for 6 hours. After 4 hours of evaporation, it was separated on a silica gel column to obtain compound 2d, where R ⁴ was tert-butyltriphenylfluorenylsilyl (-TBDPS), and the yield was 77%.

This product 2d was used to replace 2a in Example 1, and was reacted with compound 3 to prepare compound 6d as described in step (4), with a yield of 77.9%.

The compound 6d was substituted for 6a, and the final product 9b was prepared as in Example 2 with a yield of 65%.

Here is a brief representation of the process:

TdDp5

f-ΤΒΡΡ5 Example 4

1 mole of compound 2c prepared in Example 2 was dissolved in 95% trichloroacetic acid, stirred at room temperature for 2 hours, and the excess trichloroacetic acid was evaporated to dryness under reduced pressure. 10 ml of pyridine, 2 ml of acetic anhydride were directly added to the reaction system, and room temperature The mixture was stirred for 6 hours. After evaporation to dryness, it was separated on a silica gel column to obtain compound 2e with a yield of 61%.

This product was used to replace 2a in (4) of Example 1 and react with compound 3 to prepare compound 6e with a yield of 67.7%.

Substituting compound 6e for 6a, the final product 9b was prepared as in Example 2 with a yield of 59%. reaction process:

Example 5

The compound 2d prepared in Example 3 was used instead of 2c, and the compound 2e was prepared in the same manner as in Example 4 to further prepare the product 9b with a yield of 59%. Example 6

Another method for the synthesis of trisaccharide donor compounds (about this method, the applicant has described it in detail in another earlier application).

D-glucose la was added to an acryl alcohol solution containing 0.6M hydrochloric acid gas, stirred under heating and reflux for 24 hours, and then evaporated to dryness under reduced pressure, using a methanol-ethyl acetate mixture of 1: 2 ~ 1: 5 as a shower solution. The washing solution was used to separate the reaction product on a silica gel column to obtain allyl glucoside of glucose with a structural formula of 99 and a yield of 64%.

Take 10 g of allyl glycoside, 20 ml of formaldehyde, 5 ml of triethyl orthoformate, and add them to 100-150 ml of dried diamidylformamide in order, and heat and stir at 80 ° C for 6 hours. The reaction is completed by TLC. After that, the reaction solution was cooled to room temperature, poured into about 300 ml of cold water, and extracted with dichloromethane. The organic phase was collected and concentrated under reduced pressure. The obtained concentrated product was separated on a silica gel column to obtain 4,6-benzylidene glucoallyl group. Glycoside, structural formula 101, yield 55%.

The commercially available compound 100 and the above compound 101 were mixed in an anhydrous dichloromethane in an amount of 1.2: 1, and the Lewis acid AgOTf was added at -15 ° C, and the mixture was stirred for 4 to 8 hours to perform a glycosylation reaction. The completion of the reaction was detected by TLC. After separation by a silica gel column, the disaccharide was obtained with the formula 102, and the yield was 79%.

The compound 102 was dissolved in a pyridine solution, acetic anhydride was added, and the mixture was stirred at room temperature for 4 hours, and distilled under reduced pressure to obtain a slurry. The slurry was dissolved in an organic solvent, 1,4-dioxane, and 1N Treatment with hydrochloric acid can obtain the disaccharide compound 106 with a yield of about 70%.

The commercially available compound 100 and the prepared compound 106 were repeated to repeat the glycosylation process of the above compound 102 to obtain trisaccharide 107 with a yield of 56%. 5 g of this product was dissolved in 20 ml of pyridine solution, 10 ml of acetic anhydride was added, and acetylation was carried out at room temperature with stirring for 4 hours. Trisaccharide 108 was collected by distillation under reduced pressure, and the yield was 95%.

The trisaccharide 108 and palladium chloride (PdCl ₂ ) are mixed at a molar ratio of 1: 2, dissolved in methanol, and stirred at room temperature for 4 to 8 hours to remove the protective group (allyl) at the 1-position. After the reaction was detected by TLC, the reaction solution was filtered, the filtrate was neutralized with sodium bicarbonate solution, and the reaction solution was extracted with ethyl acetate. The organic phase was concentrated under reduced pressure and separated on a silica gel column to obtain compound 109. Yield: 88%. .

The above product 109 1.5 g was reacted with 2 equivalents of diethylaminosulfur trifluoride (DAST) in dichloromethane for about 2 hours. After the completion of the detection by TLC, it was separated on a silica gel column to obtain the trisaccharide donor compound 7c. , The leaving group is F, the yield is 57%.

Compound 7c was used in place of 7b in Example 1, and 2 equivalents of silver trifluoromethanesulfonate were used as a catalyst to complete the subsequent synthesis, and the product 9b was obtained.

The implementation of the aforementioned synthetic process of the donor 7c can refer to the following route:

99 101 91

6T900 / 10N3 / X3d ΐ1 ^ 6 / ιο OAV Example 7

In step (3) of the example, after reacting compound 4a with 5a, 2.5 equivalents of benzoyl chloride and 10 ml of pyridine were sequentially added to react, and the product 7d was obtained after the same treatment, and 7b was replaced with the compound 7d.

Application Examples

Synthesis Example The polyalkylene glucosamine sugar product obtained the above embodiments formulated 10- ⁶ M, 10- ⁷ M and 10- ⁸ M aqueous concentration level, directly spraying the leaves infected with rice sheath blight experimental group The disease was monitored for 5 days after spraying. The control group was rice leaves that had not been sprayed with the same degree of Rhizoctonia solani infection. It was found that rice with glucovinose pesticides could reduce the disease. 70%.

The test data is as follows:

Test object Incidence rate (%) Cure rate (%)

Control group 99% 0

-1 10 " ⁸ Group M -79% -21%

5 X 10— ⁸ M group ~ 68% ~ 32%

1 X 10— ⁷ M group -55% -45%

5 X 10- ⁷ M group -41% ~ 59%

1 10-6M group -32% ~ 68%

5 10-6M group 〜27% -73%

Claims

Claim

1. A glucopolyene compound having a chemical structure shown by the following formula (III):

2. The method for synthesizing dextran polysaccharides according to claim 1, wherein the process comprises a regioselective coupling synthesis reaction using compounds having the general formulae (I) and (II) as reactants, and the reaction conditions include: Lewis acid is used as a catalyst in an aprotic organic solvent and reacts at a temperature below o ° C;

Wherein: L is a leaving group, which represents a prime, an ester group, and a 1-enoxy group;

RR ² and R ⁵ are the same or different acyl groups; R ³ is hydrogen; and RR ² and R ^{5 are the} same or different acyl groups.

3. The synthesis method according to claim 2, wherein the leaving group L is n-pentenyloxy.

4. The synthesis method according to claim 2, wherein the leaving group L is a trifluoroacetate group, a trichloroacetate group, a trichloroacetimide ester group, or a phosphoric acid having a structure of -ΟΡ (〇Z) ₂ An ester derivative in which ζ is benzyl, ethyl or methyl.

5. The method of claim 2, wherein R ² and R ⁵ are acetyl and benzoyl, and are the same or different.

6. The method according to claim 2, wherein the Lewis acid catalyst used is selected from the group consisting of a silver salt, a divalent mercury salt, or a trisiliconyl trifluorosulfonate, triethylsilyl trifluorosulfonate, Ν -Halogenated succinimide, boron trifluoride ether or mixtures thereof.

7. The method according to claim 2, wherein the aprotic organic solvent comprises dichloroalkane, acetonitrile, diethyl ether, benzene, toluene, or a mixed solvent thereof.

8. The method according to claim 2, further comprising the following processes for preparing reactants (I) and (II) using D-glucose as an initial raw material:

(1) Using D-glucose as a raw material, firstly formulating compounds 4, 4b, 5 and 2 respectively, wherein: L is a leaving group as defined in claim 2, or can be modified to be as defined in claim 2 by appropriate modification. The leaving groups, R ² , R ³ , and R ⁵ are all the same as in claim 2, T and P are also leaving groups, and the protecting group R ⁴ in compound 2 is hydrogen, acetyl, and phenylhydrazone. Acyl, benzyl or its derivative, triphenylfluorenyl or its derivative, alkyl silicon;

(2) Compounds 4 and 5 are prepared by using a Lewis acid as a catalyst in an anhydrous organic solvent, and the glycosylation reaction is carried out under 0 ° C under a nitrogen atmosphere, followed by a common acylation reaction to prepare a trisaccharide donor compound (I );

(3) Compounds 2 and 3 are prepared by using a Lewis acid as a catalyst in an anhydrous organic solvent and a glycosylation reaction under a nitrogen atmosphere at a temperature below 0 ° C to prepare a disaccharide compound ⁶ ;

(4) The disaccharide compound 6 and the compound 4b are glycosylated with a Lewis acid as a catalyst under a nitrogen atmosphere at a temperature of 0 ° C or lower to obtain a trisaccharide compound (Ila), and then the protective group R ⁴ is removed to become Trisaccharide receptor compounds (II).

9. The synthesis method according to claims 2 to 8, wherein when R ³ is H, the process further comprises reacting the reactants (I) and (II) to obtain an intermediate product (m _a ) first, and the intermediate product is further subjected to Deprotection group was prepared to obtain the final reaction product '(III).

Ilia

10. Use of a compound according to claim 1 in controlling plant or crop diseases and insect pests caused by fungi.

11, Use according to claim 14, wherein the compound is formulated using an aqueous solution to a molar concentration of ^10-8 ~ ^10-0 levels.

12. The compound according to claim 1 is used as a storage and fresh-keeping preparation for crops, fruit and vegetable products.

13. The application according to claim 16, wherein the compound is formulated into an aqueous solution having a molar concentration of 10-8 grade 10-6 when in use.