阅读说明：本技术 一种天牛性信息素2,3-二酮系列化合物及其衍生物的制备方法 (Preparation method of longicorn sex pheromone 2, 3-diketone series compounds and derivatives thereof ) 是由 杨晓云 曾鑫年 周琢强 陈志雪 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种天牛性信息素2,3-二酮类化合物的制备方法,本发明以含6、8、10碳的直链羧酸为原料经羧酸α-卤代、消除、还原等步骤实现系列2,3-二酮化合物的合成,该类结构经还原、手性拆分得到系列α-羟基酮手性化合物。该路线具有安全易操作、后处理简单、收率高、成本低的特点。(The invention discloses a preparation method of a longicorn sex pheromone 2, 3-diketone compound, which takes linear chain carboxylic acid containing 6, 8 and 10 carbons as a raw material to realize the synthesis of a series of 2, 3-diketone compounds through the steps of carboxylic acid alpha-halogenation, elimination, reduction and the like, and the structure is reduced and chirally resolved to obtain a series of alpha-hydroxyketone chiral compounds. The route has the characteristics of safety, easy operation, simple post-treatment, high yield and low cost.)

1. A preparation method of a longicorn sex pheromone 2, 3-diketone compound is characterized in that the synthetic route of the longicorn sex pheromone 2, 3-diketone compound is as shown in formula 1:

wherein, the structural general formula of the 2, 3-diketone compound is shown as formula 2:

wherein n is 1,3, 5.

2. The method for preparing a 2, 3-diketone compound of longicorn sex pheromone according to claim 1, characterized in that the preparation reaction formula of the 2-halogeno-alkyl carboxylate is as shown in formula 3:

wherein m is 1,3,5, n is 2,4, 6;

the method comprises the following steps:

s101, under the atmosphere of inert gas, adding corresponding carboxylic acid starting materials into thionyl chloride, reacting for 2-4 hours at 40-80 ℃, removing the thionyl chloride through vacuum concentration, and cooling to 0-room temperature;

s102, adding NXS and an initiator, heating to 80-120 ℃, reacting for 2-4 hours, and cooling to room temperature;

s103, adding alcohol for post-treatment, layering, concentrating the alcohol solution under reduced pressure to obtain a 2-halogeno-alkyl carboxylate crude product, and purifying to obtain the 2-halogeno-alkyl carboxylate with the purity of more than or equal to 98%.

3. The method for preparing a 2, 3-diketone compound of longicorn sex pheromone according to claim 1,

(E) the reaction formula for preparing the 2-alkene-1-alkyl alcohol is shown as the formula 4

Wherein n is 2,4, 6;

the method comprises the following steps:

s201, under the inert gas atmosphere, adding a 2-halogenated-alkyl carboxylic ester starting raw material into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and alkali, and reacting at room temperature of 80 ℃ below zero for 2 to 8 hours;

s202, adding aluminum lithium hydrogen to react for 2-6 hours, filtering, adding an alcohol water solution, separating an organic layer by using a separating funnel, and concentrating under reduced pressure to obtain a 2-alkene-1-alkyl alcohol crude product;

s203 is purified to obtain the 2-halogenated-alkyl carboxylic ester with the purity of more than or equal to 98 percent.

4. The method for preparing a 2, 3-diketone compound of longicorn sex pheromone according to claim 1,

(E) the reaction formula for preparing 2-alkene is shown as formula 5

Wherein n is 2,4, 6;

the method comprises the following steps:

s301, under the inert gas atmosphere, adding 2-alkene-1-alkyl alcohol into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and phosphorus trihalide, and reacting at room temperature to 60 ℃ for 2-4 hours;

s302, adding an alkaline aqueous solution, adjusting the pH value to be alkalescent, separating an organic layer, concentrating under reduced pressure to remove an organic solvent to obtain a crude product of (E) -1-halo-2-olefin, and purifying the crude product to obtain (E) -1-halo-2-olefin with the purity of more than or equal to 98%;

s303, under the inert gas atmosphere, adding the (E) 1-halogenated-2-olefin obtained in the step S302 into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and magnesium powder, and reacting at room temperature to 60 ℃ for 2-4 hours;

s304, adding an acidic aqueous solution, adjusting the pH value to be weakly acidic, separating an organic layer, carrying out reduced pressure concentration to remove an organic solvent to obtain a (E) 2-olefin crude product, and purifying to obtain 2-olefin with the purity of more than or equal to 98%.

5. The method for producing a 2, 3-dione compound from longicorn according to claim 1,

the preparation reaction formula of the 2, 3-diol compound is shown as formula 6

Wherein n is 2,4, 6;

the method comprises the following steps:

s401, under the inert gas atmosphere and ice bath condition, adding 2-olefin into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and peroxide, and reacting at 0-room temperature for 0.5-2 hours;

s402, adding water for layering, separating an organic layer, concentrating under reduced pressure to remove the organic solvent to obtain a crude product of 2, 3-diol, and purifying to obtain the 2, 3-diol with the purity of more than or equal to 98%.

6. The method for producing a 2, 3-dione compound from longicorn according to claim 1,

the preparation reaction formula of the 2, 3-diketone compound is shown as formula 7

Wherein n is 2,4, 6;

the method comprises the following steps:

s501, sequentially adding 2, 3-diol and an organic solvent under an inert gas atmosphere and an ice bath condition, then adding an oxidant, and reacting for 2-6 hours at room temperature to 80 ℃;

s502, adding acid to adjust the pH value to be neutral at room temperature, adding water to wash, decompressing and concentrating to remove the organic solvent to obtain a 2, 3-diol crude product, and purifying to obtain the 2, 3-diketone with the purity of more than or equal to 98%.

7. A preparation method of a longicorn sex pheromone 2, 3-diketone derivative is characterized in that the synthetic route of the longicorn sex pheromone 2, 3-diketone derivative is as shown in a formula 8

Wherein n is 2,4, 6.

8. The method for producing a longicorn sex pheromone 2, 3-dione derivative according to claim 7, comprising the steps of:

s601, sequentially adding 2, 3-diketone and an organic solvent under an inert gas atmosphere and ice bath condition, then adding a reducing agent, and reacting for 2-4 hours at 0-40 ℃;

s602, adding acid to adjust the pH value to be neutral, separating an organic layer by a separating funnel, carrying out reduced pressure concentration to remove an organic solvent to obtain a crude hydroxyketone product, and purifying to obtain hydroxyketone with the purity of more than or equal to 98%;

s603, a high performance liquid chromatography chiral stationary phase method is adopted, cyclodextrin grafted polysiloxane is used as a chiral stationary phase, saturated alkane-alcohol is used as a mobile phase, and chiral resolution of (R), (S) -3-hydroxy-2-ketone and (R), (S) -2-hydroxy-3-ketone derivatives is realized.

Background

Longicorn is one of important pests with extremely strong destructive power for the healthy growth of trees, adults gnaw tender tips and veins, young worms erode the phloem and saplings of trees, and the xylem is eroded into irregular pores, so that the physiological function of trees is seriously destroyed, and finally the trees die.

With the intensive research on the longicorn pheromone, the sex pheromone compound technology is beneficial to improving the trapping amount of the longicorn in the forest, and has extremely important significance for monitoring the population dynamics of the longicorn and preventing and controlling the longicorn in a pollution-free manner.

Sex pheromones are produced by both male and female longicorn. The sex pheromone components produced by male Anelaphus inflationalis include (R) -3-hydroxyhexan-2-one, (S) -2-hydroxyhexan-3-one, 2, 3-hexanedione, (2R, 3R) -2, 3-hexanediols and (2R, 3S) -2, 3-hexanediols. The field test shows that single (R) -3-hydroxyhexan-2-one can attract longicorn to gather, other trace components have synergistic effect, and the composition of the above-mentioned sex pheromone has a common structural diagram, and its two-carbon or three-carbon position has six-carbon, eight-carbon or ten-carbon straight chain of hydroxyl group or carbonyl group.

At present, in the aspect of synthesizing 2, 3-diketone compounds, Roelixia and the like obtain 2, 3-hexanedione by using acetaldehyde and 2-butanone through an aldol condensation method; zhaojunxia, etc. is formed by the reaction of acetaldehyde with hexanal (48%); rueedi et al obtained 2, 3-didecanone (81%) from commercially unavailable 2-decanone via nitrous acid. The above methods have respective disadvantages of low yield, difficulty in supplying raw materials, and the like.

Disclosure of Invention

The invention overcomes the defects of the prior art, and provides a general synthesis method of 2, 3-diketone compounds with easily obtained raw materials and high yield. In order to achieve the purpose, the invention adopts the technical scheme that:

a method for preparing longicorn sex pheromone 2, 3-diketone compounds is disclosed, wherein the synthetic route of the longicorn sex pheromone 2, 3-diketone compounds is as shown in formula 1:

wherein, the structural general formula of the 2, 3-diketone compound is shown as formula 2:

wherein n is 1,3, 5.

In a preferred embodiment of the present invention, there is further provided a process for preparing a 2-halo-alkyl carboxylate, according to the formula of formula 3:

wherein m is 1,3,5, n is 2,4, 6;

the method comprises the following steps:

s101, under the atmosphere of inert gas, adding corresponding carboxylic acid starting materials into thionyl chloride, reacting for 2-4 hours at 40-80 ℃, removing the thionyl chloride through vacuum concentration, and cooling to 0-room temperature;

s102, adding NXS and an initiator, heating to 80-120 ℃, reacting for 2-4 hours, and cooling to room temperature;

s103, adding alcohol for post-treatment, layering, concentrating the alcohol solution under reduced pressure to obtain a 2-halogeno-alkyl carboxylate crude product, and purifying to obtain the 2-halogeno-alkyl carboxylate with the purity of more than or equal to 98%.

The room temperature range of the invention is 15-35 ℃.

Preferably, the molar ratio of the carboxylic acid to the thionyl chloride to the NXS to the initiator to the alcohol is 1 (1.05-3): (1.05-2):(0.05-1):(10-30).

Preferably, the carboxylic acid is n-hexanoic acid, n-heptanoic acid and n-decanoic acid.

Preferably, the NXS is N-bromosuccinimide, N-chlorosuccinimide or N-iodosuccinimide

Preferably, the initiator is cyclohexanone peroxide, dibenzoyl peroxide, tert-butyl hydroperoxide, azobisisobutyronitrile and azobisisoheptonitrile.

Preferably, the alcohol is methanol, ethanol, propanol, isopropanol, or tert-butanol.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the crude 2-halo-alkyl carboxylate is purified by column chromatography to obtain a pure 2-halo-alkyl carboxylate.

In a preferred embodiment of the present invention further comprising,

(E) the reaction formula for preparing the 2-alkene-1-alkyl alcohol is shown as the formula 4

Wherein n is 2,4, 6;

the method comprises the following steps:

s201, under the inert gas atmosphere, adding a 2-halogenated-alkyl carboxylic ester starting raw material into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and alkali, and reacting at room temperature of 80 ℃ below zero for 2 to 8 hours;

s202, adding aluminum lithium hydrogen to react for 2-6 hours, filtering, adding an alcohol water solution, separating an organic layer by using a separating funnel, and concentrating under reduced pressure to obtain a 2-alkene-1-alkyl alcohol crude product;

s203 is purified to obtain the 2-halogenated-alkyl carboxylic ester with the purity of more than or equal to 98 percent.

The room temperature range of the invention is 15-35 ℃. The carboxylic acid ester can be used directly in the subsequent reaction without purification.

Preferably, the molar ratio of the 2-halo-alkylcarboxylate to the base to the aluminum lithium hydride is 1 (1.05-4): (1.05-3).

Preferably, the 2-halo-alkylcarboxylic acid ester is 2-chloro-, bromo-or iodo-formed methyl, ethyl, propyl, isopropyl or tert-butyl ester of hexanoic, heptanoic or decanoic acid.

Preferably, the base is sodium carbonate, potassium carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, pyridine, triethylamine, tetrahydropyrrole, or cyclohexylamine.

Preferably, the solvent is tetrahydrofuran, 1, 4-dioxane and methyl tert-butyl ether.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the (E) 2-alkene-1-alkyl alcohol crude product is subjected to column purification treatment to obtain a (E) 2-alkene-1-alkyl alcohol pure product.

In a preferred embodiment of the present invention further comprising,

(E) the reaction formula for preparing 2-alkene is shown as formula 5

Wherein n is 2,4, 6;

the method comprises the following steps:

s301, under the inert gas atmosphere, adding 2-alkene-1-alkyl alcohol into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and phosphorus trihalide, and reacting at room temperature to 60 ℃ for 2-4 hours;

s302, adding an alkaline aqueous solution, adjusting the pH value to be alkalescent, separating an organic layer, concentrating under reduced pressure to remove an organic solvent to obtain a crude product of the (E) -1-halo-2-olefin, and purifying the crude product to obtain the (E) -1-halo-2-olefin with the purity of more than or equal to 98%.

Preferably, the molar ratio of the 2-ene-alkyl alcohol to the phosphorus trihalide is 1: (1.05-1.5).

Preferably, the (E) -2-ene-1-alkyl alcohol is (E) -2-ene-1-hexanol, (E) -2-ene-1-heptanol, or (E) -2-ene-1-decanol.

Preferably, the phosphorus trihalide is phosphorus trichloride or phosphorus tribromide.

Preferably, the organic solvent is dichloromethane, trichloromethane, 1, 2-dichloroethane, acetonitrile.

Preferably, the alkaline aqueous solution is an aqueous solution of sodium bicarbonate, potassium bicarbonate, sodium carbonate and potassium carbonate with the pH value of 8-9.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the crude (E) 1-halo-2-olefin is subjected to column purification treatment to obtain a pure (E) 1-halo-2-olefin.

S303, under the inert gas atmosphere, adding the (E) 1-halogenated-2-olefin obtained in the step S302 into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and magnesium powder, and reacting at room temperature to 60 ℃ for 2-4 hours;

s304, adding an acidic aqueous solution, adjusting the pH value to be weakly acidic, separating an organic layer, carrying out reduced pressure concentration to remove an organic solvent to obtain a (E) 2-olefin crude product, and purifying to obtain 2-olefin with the purity of more than or equal to 98%.

Preferably, the molar ratio of the (E) 1-halogenated-2-olefin to the magnesium powder is 1 (1.05-1.5).

Preferably, the (E) 1-halo-2-ene is (E) 1-chloro-2-hexene, (E) 1-chloro-2-heptene, (E) 1-chloro-2-decene, (E) 1-bromo-2-hexene, (E) 1-bromo-2-heptene, or (E) 1-bromo-2-decene.

Preferably, the organic solvent is diethyl ether or tetrahydrofuran.

Preferably, the acidic aqueous solution is a solution of ammonium chloride, sodium dihydrogen phosphate, potassium dihydrogen phosphate, hydrochloric acid, sulfuric acid, or phosphoric acid with a pH value of 4-6.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the crude (E) 2-olefin is subjected to column purification treatment to obtain a pure (E) 2-olefin product.

In a preferred embodiment of the present invention, further comprising,

the preparation reaction formula of the 2, 3-diol compound is shown as formula 6

Wherein n is 2,4, 6;

the method comprises the following steps:

s401, under the inert gas atmosphere and ice bath condition, adding 2-olefin into a reaction bottle with a magnetic stirrer, sequentially adding an organic solvent and peroxide, and reacting at 0-room temperature for 0.5-2 hours;

s402, adding water for layering, separating an organic layer, concentrating under reduced pressure to remove the organic solvent to obtain a crude product of 2, 3-diol, and purifying to obtain the 2, 3-diol with the purity of more than or equal to 98%.

Preferably, the molar ratio of the (E) 2-olefin to the peroxide is 1 (1.05-2).

Preferably, the (E) 2-olefin is (E) 2-hexene, (E) 2-heptene, or (E) 2-decene.

Preferably, the peroxide is m-chloroperoxybenzoic acid, peroxy-tert-butyric acid and hydrogen peroxide.

Preferably, the organic solvent is dichloromethane, trichloromethane, 1, 2-dichloroethane, acetonitrile.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the 2, 3-diol crude product is subjected to column purification treatment to obtain a 2, 3-diol pure product.

In a preferred embodiment of the present invention, further comprising,

the preparation reaction formula of the 2, 3-diketone compound is shown as formula 7

Wherein n is 2,4, 6;

the method comprises the following steps:

s501, sequentially adding 2, 3-diol and an organic solvent under an inert gas atmosphere and an ice bath condition, then adding an oxidant, and reacting for 2-6 hours at room temperature to 80 ℃;

s502, adding acid to adjust the pH value to be neutral at room temperature, adding water to wash, decompressing and concentrating to remove the organic solvent to obtain a 2, 3-diol crude product, and purifying to obtain the 2, 3-diketone with the purity of more than or equal to 98%.

Preferably, the molar ratio of the 2, 3-diol to the oxidant is 1 (2.1-4).

Preferably, the 2, 3-diol is 2, 3-hexanediol, 2, 3-heptanediol, 2, 3-decanediol.

Preferably, the oxidant is 4-acetamido-2, 2,6, 6-tetramethylpiperidine-1-oxygen, DMSO-trifluoroacetic acid, NBS-pyridine and ferric nitrate.

Preferably, the organic solvent is dichloromethane, carbon tetrachloride or 1, 2-dichloroethane.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferably, the 2, 3-diketone crude product is subjected to column purification treatment to obtain a 2, 3-diketone pure product.

In a preferred embodiment of the present invention, the synthetic route of the derivatives of the 2, 3-diketone of longicorn sex pheromone is shown in formula 8

Wherein n is 2,4, 6.

In a preferred embodiment of the present invention, the method further comprises the following steps:

s601, sequentially adding 2, 3-diketone and an organic solvent under an inert gas atmosphere and ice bath condition, then adding a reducing agent, and reacting for 2-4 hours at 0-40 ℃;

s602, adding acid to adjust the pH value to be neutral, separating an organic layer by a separating funnel, carrying out reduced pressure concentration to remove an organic solvent to obtain a crude hydroxyketone product, and purifying to obtain hydroxyketone with the purity of more than or equal to 98%;

s603, a high performance liquid chromatography chiral stationary phase method is adopted, cyclodextrin grafted polysiloxane is used as a chiral stationary phase, saturated alkane-alcohol is used as a mobile phase, and chiral resolution of (R), (S) -3-hydroxy-2-ketone and (R), (S) -2-hydroxy-3-ketone derivatives is realized.

Preferably, the molar ratio of the 2, 3-diketone to the oxidant is 1 (0.5-1.25).

Preferably, the 2, 3-diketone is 2, 3-hexanedione, 2, 3-heptanedione and 2, 3-decanedione.

Preferably, the reducing agent is sodium borohydride or aluminum lithium hydride.

Preferably, the organic solvent is diethyl ether, tetrahydrofuran, methyl tert-butyl ether, methanol, ethanol, propanol, isopropanol or tert-butanol.

Preferably, the drying and concentration under reduced pressure are performed by separating the organic solvent layer with a separatory funnel, drying with anhydrous sodium sulfate or magnesium sulfate, separating the drying agent by suction filtration, and finally concentrating under reduced pressure.

Preferred solvent combinations with saturated alkane-alcohols as mobile phase are n-hexane-isopropanol, n-hexane-tert-butanol, n-heptane-isopropanol, n-heptane-tert-butanol, n-decane-isopropanol, n-decane-tert-butanol.

Preferably, the ratio of saturated alkane-alcohol is 80:20 (V/V)% to 98: 2% (V/V).

The invention solves the defects in the background technology, and has the following beneficial effects:

the invention takes linear chain carboxylic acid containing 6, 8 and 10 carbons as raw material, and realizes the synthesis of series 2, 3-diketone compounds through the steps of carboxylic acid alpha-halogenation, elimination, reduction and the like, and the series alpha-hydroxy ketone chiral compounds are obtained through reduction and chiral resolution of the structure. The route has the characteristics of safety, easy operation, simple post-treatment, high yield and low cost. The carboxylic acid alpha-halide of the invention has the characteristic of environment-friendly production.

Detailed Description

In order that the above objects, features and advantages of the present invention may be more clearly understood, a more complete description of the present invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. The following is a description of preferred embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Example 1: preparation of 2-chloro-decacarboxylmethyl ester

Adding 17.3 g (0.1 mol) of decarboxylic acid into a 250 ml dry three-neck round-bottom flask with a reflux condenser pipe under the condition of normal temperature, adding 47.6 g (0.4 mol) of thionyl chloride under the protection of nitrogen, reacting for 3 hours at 40-80 ℃, concentrating under reduced pressure to remove the thionyl chloride, and cooling to room temperature; adding 20.0 g of N-chlorosuccinimide and an initiator, heating to 90 ℃ for reaction for 2 hours, cooling to room temperature, adding methanol for post-treatment, layering, concentrating the alcohol solution under reduced pressure to obtain a crude product of 2-chloro-deca-carboxymethyl, and separating the crude product by column chromatography (300-mesh 400-mesh silica gel powder) by using petroleum ether and ethyl acetate as an eluent to obtain 18.7g of a light yellow clear liquid of 2-chloro-deca-carboxymethyl with the purity of more than 99%, wherein the separation yield is 84.7%.

Nuclear magnetic resonance data:¹H-NMR:δ0.89(3H,t,J＝6.5Hz,CH₂CH ₃),1.34–1.21(10H,m,5*CH₂),3.67(3H,s,OCH ₃),4.21(1H,m,J＝6.5Hz,Cl-CH-CH₂),2.28-2.04(2H,m,Cl-CH-CH ₂)；

example 2: preparation of (E) 2-en-1-decanol

In a 500 ml dry three-neck round-bottom flask with a reflux condenser at normal temperature, 22.1 g (0.1 mol) of 2-chloro-deca-carboxymethyl ester is added under the protection of nitrogen, 150 ml of tetrahydrofuran and 13.7 g of potassium carbonate are sequentially added, and the temperature is raised to 60 ℃ for reaction for 4 hours; and then adding aluminum lithium hydrogen to react for 2-6 hours, performing suction filtration, adding 30 ml of 30% (v/v) alcohol aqueous solution, separating a tetrahydrofuran layer by a separating funnel, adding anhydrous magnesium sulfate to dry, performing suction filtration to separate a drying agent, performing reduced pressure evaporation to remove tetrahydrofuran to obtain a crude product of (E) 2-alkene-1-decanol, and purifying to obtain 12.8 g of colorless transparent liquid of (E) 2-alkene-1-decanol with the purity of more than 99%, wherein the separation yield is 82.1%.

Nuclear magnetic resonance data:¹H-NMR:δ0.92(3H,t,J＝6.5Hz,CH₂CH ₃),1.31–1.46(10H,m,5*CH₂),2.10(2H,q,J＝6.5Hz,HO-CH2CH＝CHCH ₂),4.22(2H,d,J＝6.0Hz,OH-CH ₂),5.53–5.73(2H,m,HO-CH2CH＝CH)；

example 3: preparation of (E) 1-bromo-2-decene

Adding 15.6 g (0.10 mol) of (E) 2-alkene-1-decanol into 500 ml of a dry three-mouth round-bottom flask with a reflux condenser pipe under the condition of normal temperature, adding 200 ml of 1, 2-dichloroethane and 40.6 g (0.15 mol) of phosphorus tribromide in sequence under the protection of nitrogen, heating to 60 ℃ for reaction for 3 hours, cooling to room temperature, adding a sodium bicarbonate solution to adjust the pH value to be neutral, separating an organic solvent layer by a separating funnel, adding anhydrous magnesium sulfate for drying, filtering and separating a drying agent, evaporating 1, 2-dichloroethane under reduced pressure to obtain a (E) 1-bromo-2-decene crude product, using petroleum ether and ethyl acetate as eluents for the crude product, performing gradient elution, performing column chromatography separation (300-400-mesh silica gel powder), and obtaining 16.5 g of light yellow (E) 1-bromo-2-decene liquid with the purity of more than 99 percent, the yield thereof was found to be 75.2%.

Nuclear magnetic resonance data:¹H-NMR:δ0.87(3H,t,J＝6.5Hz,CH₂CH ₃),1.21–1.32(8H,m,4*CH₂),1.38(2H,m,J＝7.0Hz,CH＝CH-CH₂-CH ₂),2.11(2H,q,J＝7.0Hz,CH＝CH-CH ₂-CH₂),3.99(2H,d,J＝8.0Hz,Br-CH ₂),5.55-5.56(1H,m,Br-CH₂-CH＝CH),5.67–5.74(1H,m,Br-CH₂-CH＝CH)；

example 4: preparation of (E) 2-decene

Under the condition of normal temperature, 21.9 g (0.10 mol) of (E) 1-bromo-2-decene is added into a 500 ml dry three-mouth round-bottom flask with a reflux condenser tube under the protection of nitrogen, 200 ml of tetrahydrofuran and 3.0 g (0.13 mol) of magnesium powder are sequentially added, the temperature is raised to 50 ℃ for reaction for 3 hours, then sodium dihydrogen phosphate saturated solution is added, the pH value is adjusted to be neutral, an organic layer is separated, anhydrous magnesium sulfate is added for drying, a suction filtration separation drying agent is added, an organic solvent is removed by decompression and concentration to obtain a crude product of (E) -2-alkene, the crude product takes petroleum ether and ethyl acetate as eluent, gradient elution is adopted, column chromatography separation (300-400-mesh silica gel powder) is carried out, and colorless transparent (E) 2-decene liquid with the purity of more than 99% is obtained, wherein the yield is 91.2%.

Nuclear magnetic resonance data:¹H-NMR:δ0.84(3H,t,J＝6.5Hz,CH₂CH ₃),1.27-1.28(10H,m,5*CH₂),1.43(3H,m,CH ₃-CH＝CH),2.01-2.07(2H,m,CH＝CH-CH ₂),5.37-5.45(2H,m,CH₃-CH＝CH-CH₂)；

example 5: preparation of 2, 3-didecanol

Under ice bath condition, 14.0 g (0.1 mol) of (E) 2-decene is added into a 500 ml dry three-neck round-bottom flask with a reflux condenser tube under the protection of nitrogen, 200 ml of dichloromethane organic solvent and 21.6 g (0.13 mol) of m-chloroperoxybenzoic acid are sequentially added, after the mixture is heated to room temperature and reacts for 1 hour, saturated ammonium chloride aqueous solution is separated out of an organic layer, anhydrous magnesium sulfate is added for drying, a drying agent is filtered and separated by suction, reduced pressure concentration is carried out to remove the organic solvent, a 2, 3-diol crude product is obtained after the organic solvent is removed by reduced pressure concentration, petroleum ether and ethyl acetate are used as eluent, gradient elution is adopted for the crude product, and after column chromatography separation (300-400-mesh silica gel powder), colorless transparent 2, 3-didecanol liquid with the purity of more than 99 percent is obtained, 16.5 g and 94.6 percent.

Nuclear magnetic resonance data:¹H-NMR:δ0.89(3H,t,J＝6.6Hz,CH₂CH ₃),1.18(3H,d,J＝6.3Hz,CH ₃-CHOH),1.50–1.22(12H,m,6*CH ₂),2.47–2.41(2H,m,2*OH),3.48–3.46(1H,m,CH₂-CHOH),3.58(1H,quint,J＝6.3Hz,CH₃–CHOH)；

example 6: preparation of 2, 3-didecanone

Adding 17.4 g (0.10 mol) of 2, 3-didecyl alcohol into a 500 ml dry three-neck round-bottom flask with a reflux condenser pipe under the condition of normal temperature, sequentially adding 200 ml of 1, 2-dichloroethane and 53.5 g (0.25 mol) of 4-acetamido-2, 2,6, 6-tetramethylpiperidine-1-oxygen, heating to 40 ℃ for reaction for 4 hours, then adding saturated sodium dihydrogen phosphate, adjusting pH value to be neutral, separating an organic layer, adding anhydrous magnesium sulfate for drying, performing suction filtration and separation on a drying agent, performing reduced pressure concentration to remove an organic solvent to obtain a crude product of 2, 3-didecyl, performing gradient elution on the crude product by using petroleum ether and ethyl acetate as an eluent, performing column chromatography separation (300-mesh 400-mesh silica gel powder), the obtained colorless and transparent 2, 3-didecanone liquid with the purity of more than 99 percent is 15.3 g, and the yield is 90.1 percent.

Nuclear magnetic resonance data:¹H-NMR:δ0.86(3H,t,J＝7Hz,CH₂CH ₃),1.27(8H,m,4*CH ₂),1.56(2H,m,J＝7Hz,CH₂-CH ₂-CH₂–C＝O),2.31(3H,s,CH ₃-C＝O),2.71(2H,t,J＝7Hz,CH ₂–C＝O)；

example 7 preparation of 2-hydroxy-3-decanone and 3-hydroxy-2-decanone

Adding 17.0 g (0.1 mol) of 2, 3-didecanone into a 500 ml dry three-mouth round-bottom flask with a reflux condenser tube under ice bath condition, sequentially adding 200 ml of methanol and 2.1 g (0.06 mol) of sodium borohydride under the protection of nitrogen, naturally heating to room temperature for reaction for 4 hours, adding saturated sodium dihydrogen phosphate to adjust the pH value to be neutral, decompressing and concentrating to remove the methanol solvent, adding 300 ml of dichloromethane for extraction, separating an organic layer by a separating funnel, adding anhydrous magnesium sulfate for drying, performing suction filtration and separation of a drying agent, decompressing and concentrating to remove the organic solvent to obtain 2-hydroxy-3-decanone and a 2-hydroxy-3-decanone crude product, performing gradient elution by using petroleum ether and ethyl acetate as eluent, performing column chromatography separation (300-400-mesh silica gel powder), and obtaining colorless and transparent 9.1 g of 2-hydroxy-3-decanone with the purity of more than 99 percent, 6.1 g of 3-hydroxy-2-decanone, total yield 88.2%.

Nuclear magnetic resonance data: 2-hydroxy-3-decanones¹H-NMR:δ0.88(3H,t,J＝6.9Hz,CH₂CH ₃),1.27(8H,m,4*CH₂),1.38(3H,d,J＝6.9Hz,CH ₃CHOH),1.61(2H,m,CH ₂-CH₂-C＝O

),2.41(1H,dt,J＝16.8,7.6Hz,CH2-CHH-C＝O),2.52(1H,dt,J＝16.8,7.6Hz,CH2--CHH-C＝O),3.35(1H,d,J＝4.5Hz,CH-OH),4.24(1H,dq,J＝7.1,4.5Hz,CH₃CHOH)；

3-hydroxy-2-decanone:¹H-NMR:δ0.88(3H,t,J＝6.9Hz,CH₂CH ₃),1.50-1.22(12H,m,6*CH₂),2.08(3H,s,CH ₃CH＝O),3.35(1H,d,J＝4.5Hz,CH-OH),4.24(1H,m,OH-CH-CH₂)；

the 2, 3-diketone compounds prepared by the method of the invention are: 2, 3-hexanedione, 2, 3-heptanedione, 2, 3-decanedione. The derivative structure comprises (2S) -2-hydroxy-3-hexanone, decanone, (2R) -2-hydroxy-3-hexanone; (3S) 3-hydroxy-2-hexanone, (3R) -3-hydroxy-2-hexanone; (2S) -2-hydroxy-3-heptanone, (2R) -2-hydroxy-3-heptanone, (3S) 3-hydroxy-2-heptanone, (3R) -3-hydroxy-2-heptanone; (2S) -2-hydroxy-3-decanone, (2R) -2-hydroxy-3-decanone, (3S) 3-hydroxy-2-decanone, and (3R) -3-hydroxy-2-decanone.

The invention takes linear chain carboxylic acid containing 6, 8 and 10 carbons as raw material, and realizes the synthesis of series 2, 3-diketone compounds through the steps of carboxylic acid alpha-halogenation, elimination, reduction and the like, and the series alpha-hydroxy ketone chiral compounds are obtained through reduction and chiral resolution of the structure. The route has the characteristics of safety, easy operation, simple post-treatment, high yield and low cost. The carboxylic acid alpha-halogenation is characterized by environment-friendly production.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.