Method for preparing nervonic acid

Abstract

The invention relates to a method for preparing nervonic acid. The method comprises the following steps: S1, enabling erucic acid to react with acrolein under light irradiation in the presence of a photosensitizer, so as to obtain a compound as shown in a formula (I); the photosensitizer is selected from CeCl3 and / or Fe (OAc) 2; and S2, carrying out oxidation reaction on the compound as shown in the formula (I) prepared in the step S1 to obtain the nervonic acid. The method provided by the invention has the advantages of simple reaction steps and low cost.

Description

Technical Field

[0001] This invention relates to the field of organic chemical synthesis, and in particular to a method for preparing nervonic acid. Background Technology

[0002] Nervonic acid, scientifically known as cis-15-tetracosenoic acid, is an omega-9 long-chain monounsaturated fatty acid. In vivo, it is mainly distributed in nerve tissue, brain white matter, and myelin sheath, and is a key structural component for maintaining normal nervous system function. The core functions of nervonic acid include: promoting myelin formation and repair (improving demyelinating diseases such as multiple sclerosis), supporting infant brain development (containing approximately 0.2-0.5% in breast milk), improving cognitive impairment in neurodegenerative diseases such as Alzheimer's disease (by regulating nerve cell membrane fluidity and reducing β-amyloid protein deposition), and anti-inflammatory and antioxidant effects (inhibiting inflammatory factors such as TNF-α and IL-6). Currently, China has approved nervonic acid as a new resource food ingredient, with broad application prospects in brain health supplements and medicinal foods. In the future, with technological advancements, nervonic acid is expected to play an even greater role in the treatment and nutrition of neurodegenerative diseases.

[0003] Its production mainly comes from two major sources: natural extraction and artificial synthesis. Natural extraction is mainly obtained from special plant oils such as Acer truncatum seed oil (content of about 5-7%), garlic fruit oil (content of up to 60-70%), and prickly pear oil through processes such as low-temperature pressing, molecular distillation, and chromatographic separation. It can also be extracted from animal brain tissue, but natural extraction is costly, has low yield, and is limited by ethical and resource issues.

[0004] Artificial synthesis includes both chemical and biosynthetic methods. Biosynthesis utilizes genetically engineered yeast or microalgae (such as those overexpressing key enzymes like ELOVL1 / FADS2) for microbial fermentation. While environmentally friendly, current yields are only at the mg / L level. The main bottlenecks to current industrialization include: the cost of high-purity (>90%) natural extracts exceeding $5000 / kg, the difficulty in scaling up chemical synthesis, and the low efficiency of biosynthesis. Natural extraction is costly and yields low, while chemical synthesis faces challenges such as complex long carbon chain construction, high stereoselectivity requirements, and high costs. Microbial fermentation and genetic engineering are potential directions, but their current efficiency is insufficient. Nervonic acid has been used in brain health supplements and food additives, but large-scale production still requires breakthroughs in synthetic biology or plant breeding technologies.

[0005] Currently, the chemical synthesis methods for nervonic acid still face numerous challenges in industrial applications, with each patent employing its own limitations. Patent CN 111423320 B, employing a multi-step synthetic route involving esterification, reduction, bromination, ethylene oxide ring-opening, and iodobenzene acetate oxidation, while feasible, suffers from lengthy steps, low overall yield, and high costs for some reagents (such as iodobenzene acetate), hindering large-scale production. Patent CN 118184506A uses 14-bromo-1-tetradecaneol as a starting material, synthesizing nervonic acid through DHP protection, carbon chain extension with n-butyllithium, Jones oxidation, and Z-type hydrogenation reduction. However, this method relies on expensive starting materials, further increasing costs if synthesized in-house. Furthermore, the use of n-butyllithium requires stringent reaction conditions (anhydrous and oxygen-free), posing safety risks during scale-up production. Jones oxidation involves highly toxic chromium reagents, and large-scale production would impose significant environmental pressures, contradicting the trend towards green chemistry. Patents CN 116730820 A, CN 116514648 A, CN115417759 B, and CN 115490586 A all use erucic acid as a raw material to synthesize nervonic acid through carbon chain elongation. Although the source of the raw material is relatively clear, these methods still have the following problems: high dependence on raw materials—high purity erucic acid is required, and if the supply is limited, it will affect the stability of production; difficulty in controlling stereoselectivity—the hydrogenation step may produce non-target isomers, affecting the purity of the product; insufficient optimization of the catalytic system—some methods rely on precious metal catalysts or high-cost reagents, resulting in poor economic efficiency. Summary of the Invention

[0006] In view of the shortcomings of the prior art mentioned above, the present invention provides a novel and low-cost photocatalytic system for synthesizing nervonic acid.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention provides a method for preparing nervonic acid, the method comprising the following steps: Step S1: Erucic acid is reacted with acrolein in the presence of a photosensitizer and under light irradiation to obtain the compound shown in formula (I); the photosensitizer is selected from CeCl3 and / or Fe(OAc)2;

[0008] Step S2: The compound of formula (I) prepared in step S1 is subjected to an oxidation reaction to obtain the nervonic acid.

[0009] Preferably, the light irradiation is performed using light with a wavelength of 400~460nm, and more preferably, the wavelength of the light irradiation is 420~460nm.

[0010] Preferably, the molar ratio of erucic acid to acrolein is 1:1 to 5, more preferably 1:1 to 3.

[0011] Preferably, the molar ratio of erucic acid to photosensitizer is 1:0.05~1, more preferably 1:0.05~0.5.

[0012] Preferably, the reaction is carried out in the presence of an additive selected from one or more of tetrabutylammonium hexafluorophosphate, tetraethylammonium hexafluorophosphate, tetramethylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetraethylammonium tetrafluoroborate, tetrabutylammonium chloride, and tetrabutylammonium bromide.

[0013] Preferably, the reaction is carried out in the presence of a base.

[0014] Preferably, the alkali is an inorganic alkali or an organic alkali.

[0015] Preferably, the organic base is selected from one or more of triethylamine, tributylamine, N,N-diisopropylethylamine, tribenzylamine, 1,4-diazabicyclo[2.2.2]octane, 2,6-dimethylpyridine, 1,8-diazabicycloundec-7-ene, N-ethylmorpholine, tetrabutylammonium acetate, triphenylphosphine, triethylphosphine, tributylphosphine, and triethyl phosphite; The inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and calcium carbonate.

[0016] Preferably, the photosensitizer is CeCl3, and the reaction is carried out in the presence of an oxidant, wherein the oxidant is selected from one or more of peroxides, persulfates, hypochlorites, permanganates, and ozone.

[0017] Preferably, the oxidant is a persulfate, which is selected from one or more of persulfate, potassium persulfate, potassium hydrogen persulfate, and ammonium persulfate.

[0018] Preferably, the molar ratio of erucic acid to the oxidant is 1:0.1~5.

[0019] Preferably, the molar ratio of erucic acid to the oxidant is 1:0.5~5.

[0020] Preferably, the photosensitizer is Fe(OAc)2, and the reaction is carried out in the presence of a Lewis acid; The Lewis acid is selected from one or more of FeCl3, CuCl, CuSO4, Cu(hfac)2, Cu(acac)2, and AlCl3, preferably FeCl3 and / or CuCl.

[0021] Compared with the prior art, the present invention has the following superior effects: This invention provides a synthetic method that uses inexpensive and readily available cerium chloride or ferrous acetate as photosensitizers, and forms free radicals by decarboxylation of erucic acid, which then undergo 1,4-addition with acrolein to form the compound shown in formula (I). The method provided by this invention has the advantages of high yield, high purity, and low cost.

[0022] Furthermore, the compound shown in formula (I) can be oxidized to obtain nervonic acid. The method for synthesizing nervonic acid provided by this invention greatly simplifies the reaction steps, reduces costs, and is an efficient, simple, and green method that is more conducive to industrial production. Attached Figure Description

[0023] Figure 1 For the compound shown in formula (I) 1 H NMR spectrum; Figure 2 For the compound shown in formula (I) 13 C NMR spectrum; Figure 3 For nervonic acid 1 H NMR spectrum; Figure 4 For nervonic acid 13 C NMR spectrum. Detailed Implementation

[0024] To make the technical solution and beneficial effects of the present invention more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0025] The synthesis of nervonic acid from either erucic acid or more expensive starting materials inevitably involves cumbersome procedures, demanding conditions, and unstable reagents, such as organolithium reagents, Grignard reagents, and strict anhydrous and oxygen-free environments. While some methods utilize photoreaction synthesis, their over-reliance on expensive photosensitizers like TiO2 makes cost reduction difficult in large-scale production. Therefore, this invention, based on extensive and in-depth research, provides a method for synthesizing nervonic acid using cerium chloride or ferrous acetate as a photosensitizer. This involves the decarboxylation of erucic acid to form a free radical, which then undergoes a 1,4-addition reaction with acrolein to form the compound shown in formula (I). The compound in formula (I) is then oxidized to obtain nervonic acid. The photosensitizer used in this invention is inexpensive and readily available, significantly reducing synthesis costs. Furthermore, the synthesis method provided by this invention greatly simplifies the reaction steps, making it an efficient, simple, and green method.

[0026] This invention provides a method for preparing nervonic acid, the method comprising the following steps: Step S1: Erucic acid is reacted with acrolein in the presence of a photosensitizer and under light irradiation to obtain the compound shown in formula (I); the photosensitizer is selected from CeCl3 and / or Fe(OAc)2;

[0027] Step S2: The compound of formula (I) prepared in step S1 is subjected to an oxidation reaction to obtain the nervonic acid.

[0028] In some embodiments, the light irradiation is performed using light with a wavelength of 400-460nm, such as 400nm, 405nm, 410nm, 415nm, 420nm, 425nm, 430nm, 440nm, 450nm, 460nm, etc.

[0029] In some embodiments, the wavelength of the light irradiation is 420~460nm.

[0030] In some embodiments, the molar ratio of erucic acid to acrolein is 1:1 to 5, for example 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, or 1:5.

[0031] In some embodiments, the molar ratio of erucic acid to acrolein is 1:1 to 3.

[0032] In some embodiments, the molar ratio of erucic acid to acrolein is 1:1.5 to 2.5.

[0033] In some embodiments, the molar ratio of erucic acid to the photosensitizer is 1:0.05 to 1, for example, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, 1:0.11, 1:0.12, 1:0.13, 1:0.14, 1:0.15, 1:0.16, 1:0.17, 1:0.18, 1:0.19, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:1, etc.

[0034] In some embodiments, the molar ratio of erucic acid to the photosensitizer is 1:0.05~0.5.

[0035] In some embodiments, the molar ratio of erucic acid to the photosensitizer is 1:0.05~0.2.

[0036] In some embodiments, the molar ratio of erucic acid to the photosensitizer is 1:0.05~0.15.

[0037] In some embodiments, the reaction is carried out in the presence of an additive selected from one or more of tetrabutylammonium hexafluorophosphate, tetraethylammonium hexafluorophosphate, tetramethylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetraethylammonium tetrafluoroborate, tetrabutylammonium chloride, and tetrabutylammonium bromide.

[0038] In some embodiments, the reaction is carried out in the presence of a base.

[0039] In some embodiments, the base is an inorganic base or an organic base.

[0040] In some embodiments, the organic base is selected from one or more of triethylamine, tributylamine, N,N-diisopropylethylamine, tribenzylamine, 1,4-diazabicyclo[2.2.2]octane, 2,6-dimethylpyridine, 1,8-diazabicycloundec-7-ene, N-ethylmorpholine, tetrabutylammonium acetate, triphenylphosphine, triethylphosphine, tributylphosphine, and triethyl phosphite; The inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and calcium carbonate.

[0041] In some embodiments, the photosensitizer is CeCl3, and the reaction is carried out in the presence of an oxidant selected from peroxides, persulfates, hypochlorites, permanganates, and ozone.

[0042] In this application, CeCl3 can be anhydrous crystalline CeCl3 or CeCl3 hydrate. In a specific embodiment, the CeCl3 hydrate is CeCl3·7H2O.

[0043] In some embodiments, the oxidant is a persulfate, which is selected from one or more of persulfate, potassium persulfate, potassium hydrogen persulfate, and ammonium persulfate.

[0044] In some embodiments, the molar ratio of erucic acid to the oxidant is 1:0.1 to 5, for example, 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0045] In some embodiments, the molar ratio of erucic acid to the oxidant is 1:0.5~5.

[0046] In some embodiments, the molar ratio of erucic acid to the oxidant is 1:1 to 3.

[0047] In some embodiments, the photosensitizer is Fe(OAc)2, and the reaction is carried out in the presence of a Lewis acid; The Lewis acid is selected from one or more of FeCl3, CuCl, CuSO4, Cu(hfac)2, Cu(acac)2, and AlCl3, preferably FeCl3 and / or CuCl.

[0048] The molar ratio of erucic acid to Lewis acid is 1:0.1 to 0.5, for example, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, or 1:0.5.

[0049] In this invention, the solvent is not limited in steps S1 and S2, as long as it allows the reaction to proceed smoothly.

[0050] In some embodiments, the reaction in step S1 is carried out in solvent A, which is selected from nitrile solvents and haloalkane solvents. In a specific example, the nitrile solvent is selected from acetonitrile solution, and the haloalkane solvent is selected from dichloromethane.

[0051] In some embodiments, the duration of the reaction in control step S1 is 5 to 30 hours, for example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, etc.

[0052] In some embodiments, the reaction described in step S1 is carried out under a nitrogen atmosphere.

[0053] In some embodiments, step S1 further includes a post-processing step, which includes quenching, extracting, drying, filtering, concentrating, and chromatographically purifying the reaction product to obtain the compound shown in formula (I).

[0054] In some embodiments, the oxidation reaction in step S2 is not limited, and any reaction that can proceed smoothly is acceptable. This includes, but is not limited to: Pinnick oxidation using NaClO2 as the oxidant; Jones oxidation or PDC oxidation (Pyridinium Dichromate oxidation); and more environmentally friendly TEMPO / NaOCl oxidation, asamylene oxidation using oxygen catalyzed by iron, and the 1-hydroxycyclohexylphenyl ketone oxidation system, etc.

[0055] In some embodiments, the oxidation reaction in step S2 is carried out using 1-hydroxycyclohexylphenyl ketone as the oxidant system.

[0056] In some embodiments, the oxidation reaction in step S2 is carried out under alkaline conditions.

[0057] In some embodiments, the reaction in step S2 is carried out in solvent B, which is selected from ether solvents. In a specific example, the ether solvent is diethoxymethane.

[0058] In some embodiments, the temperature of the oxidation reaction is controlled at 70~100°C, preferably 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, or 100°C.

[0059] In some embodiments, the duration of the oxidation reaction is controlled to be 2 to 10 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.

[0060] In some embodiments, step S2 further includes a post-processing step, which includes quenching, extracting, drying, filtering, concentrating, and chromatographically purifying the reaction product to obtain the nervonic acid.

[0061] The method of the present invention will be described below through specific embodiments. It should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0062] The following examples 1 ¹H NMR was obtained using a Bruker instrument (400 MHz), and chemical shifts are expressed in ppm. Tetramethylsilane internal standard (0.00 ppm) was used. 1 H NMR representation: s = singlet, d = doublet, t = triplet, q = quartet, m = multiply, br = broad peak, dd = doublet of doublet, dt = doublet of triplet. When the coupling constant is provided, its unit is Hz.

[0063] TLC: Thin-layer chromatography. Yantai Huanghai HSGF254 or Qingdao GF254 silica gel plates are used for TLC. The silica gel plates used in TLC have a diameter of 0.2 mm to 0.3 mm, and the diameter used for TLC separation and purification of products is 0.4 mm to 0.5 mm.

[0064] Column chromatography typically uses Yantai Huanghai silica gel with a mesh size of 200-300 as the carrier.

[0065] In the following examples, unless otherwise specified, all temperatures are in Celsius; unless otherwise specified, all starting materials and reagents are commercially available or synthesized according to known methods; commercially available materials and reagents are used directly without further purification; unless otherwise specified, commercially available manufacturers include, but are not limited to, Sinopharm Group, Bailingwei Technology Co., Ltd., TCI (Shanghai) Chemical Industry Development Co., Ltd., Shanghai Bid Pharmaceutical Technology Co., Ltd., and Shanghai Mairui Chemical Technology Co., Ltd.

[0066] Unless otherwise specified in the examples, the solution in the reaction refers to an aqueous solution.

[0067] Unless otherwise specified in the examples, the reaction temperature is room temperature, which is 20 ℃ ~ 30 ℃.

[0068] The reaction process in the examples was monitored using thin-layer chromatography (TLC). The developing solvent used in the reaction, the eluent system used for column chromatography to purify the compounds, or the developing solvent system for TLC included: A: petroleum ether and ethyl acetate system; B: dichloromethane and methanol system; C: n-hexane: ethyl acetate. The volume ratio of the solvent varied depending on the polarity of the compound and could also be adjusted by adding a small amount of acidic or basic reagents, such as acetic acid or triethylamine.

[0069] Example 1 (1) Synthesis of the compound shown in formula (I)

[0070] 33.9 mg erucic acid (0.1 mmol), 2.4 mg cerium chloride, 6.6 mg cesium carbonate, 113.7 mg tetrabutylammonium hexafluorophosphate, and 58.2 mg potassium persulfate were weighed into a round-bottom flask, and the atmosphere was evacuated to nitrogen. Then, 65 μL of water, 2 mL of acetonitrile, and 15 μL of acrolein were added. The mixture was irradiated under an LED lamp at a wavelength of 420 nm for 8 hours. After the reaction was completed by TLC, 1 M hydrochloric acid was added to quench the reaction, followed by dilution with saturated ammonium chloride solution. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, and the combined organic phases were concentrated under reduced pressure. The compound of formula (I) was purified by rapid column chromatography, yielding 39.8 mg, with a yield of 71%.

[0071]

[0072]

[0073] (2) Synthesis of nervonic acid

[0074] 39.8 mg of the compound shown in formula (I), 21.3 mg of 1-hydroxycyclohexylphenyl ketone, 8.9 mg of sodium hydroxide, and 4 mL of DME were added to a round-bottom flask and reacted at 80 °C for 4 hours. 1 M HCl was added, the mixture was diluted with water and extracted with ethyl acetate. The combined organic phases were dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by rapid column chromatography to obtain the target product nervonic acid in a yield of 81.4%.

[0075]

[0076]

[0077] Example 2 (1) Synthesis of the compound shown in formula (I) The synthesis of the compound shown in formula (I) in this embodiment is basically the same as that in Example 1, except that tetrabutylammonium hexafluorophosphate and potassium persulfate are not added during the reaction process, and the reaction time is extended to 18 hours in this embodiment. The yield is 34%.

[0078] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 1.

[0079] Example 3 (1) Synthesis of the compound shown in formula (I) The synthesis of the compound shown in formula (I) in this embodiment is basically the same as that in Example 1, except that the amount of potassium persulfate used is different. In this embodiment, the amount of potassium persulfate used is about 1 / 4 of that in Example 1, 0.5 eq. The yield is 58%.

[0080] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 1.

[0081] Example 4 (1) Synthesis of the compound shown in formula (I)

[0082] 32.3 mg of erucic acid, 1.7 mg of ferrous acetate, 2.4 mg of ferric chloride, and 3.9 mg of tetrabutylammonium hexafluorophosphate were weighed into a round-bottom flask, and the atmosphere was evacuated to nitrogen. Then, 44 μL of DBU, 1.5 μL of acrolein, and 2 mL of DCM were added to the nitrogen-protected round-bottom flask. The reaction was irradiated under an LED lamp with a wavelength of 420 nm for 16 hours. After the reaction was detected by TLC, 1 M hydrochloric acid was added to quench the reaction, followed by dilution with saturated ammonium chloride solution. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, and the combined organic phases were concentrated under reduced pressure. The compound of formula (I) was purified by rapid column chromatography, yielding 22.98 mg, with a yield of 41%.

[0083] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 1.

[0084] Example 5 (1) Synthesis of the compound shown in formula (I) The synthesis of the compound shown in formula (I) in this embodiment is basically the same as that in Example 4, except that the base DBU is replaced with DABCO in the reaction process, and the amount used is still about 0.3 eq. The yield is 33%.

[0085] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 4.

[0086] Example 6 (1) Synthesis of the compound shown in formula (I) The synthesis of the compound shown in formula (I) in this embodiment is basically the same as that in Example 5, except that the additive tetrabutylammonium hexafluorophosphate is replaced with TBAC in the reaction process, and the amount used is still about 0.1 eq. The yield is 26%.

[0087] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 5.

[0088] Example 7 (1) Synthesis of the compound shown in formula (I) The synthesis of the compound shown in formula (I) in this embodiment is basically the same as that in Example 6, except that ferric chloride is replaced with cuprous chloride in the reaction process, and the amount used is still about 0.3 eq. The yield is 21%.

[0089] (2) Synthesis of nervonic acid In this embodiment, the synthesis of nervonic acid is the same as in Example 6.

[0090] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of the present invention and do not limit the scope of protection of this patent.

Claims

1. A method for preparing nervonic acid, characterized in that, The method includes the following steps: Step S1: Erucic acid is reacted with acrolein in the presence of a photosensitizer and under light irradiation to obtain the compound shown in formula (I); the photosensitizer is selected from CeCl3 and / or Fe(OAc)2; ； Step S2: The compound of formula (I) prepared in step S1 is subjected to an oxidation reaction to obtain the nervonic acid.

2. The method according to claim 1, characterized in that, The light irradiation is performed using light with a wavelength of 400~460 nm, preferably 420~460 nm.

3. The method according to claim 1, characterized in that, The molar ratio of erucic acid to acrolein is 1:1 to 5, preferably 1:1 to 3; Preferably, the molar ratio of erucic acid to photosensitizer is 1:0.05~1, more preferably 1:0.05~0.

5.

4. The method according to claim 1, characterized in that, The reaction is carried out in the presence of an additive selected from one or more of tetrabutylammonium hexafluorophosphate, tetraethylammonium hexafluorophosphate, tetramethylammonium hexafluorophosphate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium perchlorate, tetraethylammonium perchlorate, tetraethylammonium tetrafluoroborate, tetrabutylammonium chloride, and tetrabutylammonium bromide.

5. The method according to claim 1, characterized in that, The reaction is carried out in the presence of a base. Preferably, the alkali is an inorganic alkali or an organic alkali. The organic base is selected from one or more of the following: triethylamine, tributylamine, N,N-diisopropylethylamine, tribenzylamine, 1,4-diazabicyclo[2.2.2]octane, 2,6-dimethylpyridine, 1,8-diazabicycloundec-7-ene, N-ethylmorpholine, tetrabutylammonium acetate, triphenylphosphine, triethylphosphine, tributylphosphine, and triethyl phosphite; The inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, cesium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and calcium carbonate.

6. The method according to any one of claims 1 to 5, characterized in that, The photosensitizer is CeCl3, and the reaction is carried out in the presence of an oxidant, which is selected from peroxide, persulfate, hypochlorite, permanganate and ozone.

7. The method according to claim 6, characterized in that, The oxidant is a persulfate, which is selected from one or more of persulfate, potassium persulfate, potassium peroxymonosulfate, and ammonium persulfate.

8. The method according to claim 6 or 7, characterized in that, The molar ratio of erucic acid to the oxidant is 1:0.1~5.

9. The method according to claim 8, characterized in that, The molar ratio of erucic acid to the oxidant is 1:0.5~5, preferably 1:1~3.

10. The method according to any one of claims 1 to 5, characterized in that, The photosensitizer is Fe(OAc)2, and the reaction is carried out in the presence of a Lewis acid. The Lewis acid is selected from one or more of FeCl3, CuCl, CuSO4, Cu(hfac)2, Cu(acac)2, and AlCl3, preferably FeCl3 and / or CuCl.

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