Synthesis method and application of dibenzo-alpha-pyrone compound

Abstract

The invention relates to the technical field of organic synthesis, in particular to a synthesis method and application of a dibenzo-alpha-pyrone compound. The synthesis method comprises the following steps: taking a dipropiophenone compound as a raw material, using an oxidizing agent, lewis acid and an oxidation catalyst, and reacting in an organic solvent at room temperature. According to the synthesis method disclosed by the invention, the dibenzo-alpha-pyrone compound is prepared by taking the easily available benzophenone compound as a raw material through Baeyer-Villiger oxidation and Scholl oxidative coupling by a one-pot method, the reaction is simple and convenient, the condition is mild, and a more efficient and green method is provided for preparing bioactive substances such as urolithin a-c.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly relates to a method for synthesizing dibenzo-α-pyrone compounds and its application. Background Art

[0002] Dibenzo-α-pyrone compounds are an important class of natural metabolites, which are derived from fungi, plants, animal feces, etc. Such compounds exhibit various biological activities, including anti-tumor proliferation, antioxidant, anti-inflammatory, antibacterial, anti-aging, etc. For example, lithospermic acid A, which is generated from ellagitannins and ellagic acid in plants through the polyketide metabolic pathway of intestinal microorganisms, has significantly enhanced mitophagy, promoted the clearance of defective mitochondria, improved mitochondrial quality, reduced oxidative stress, and thus can slow down healthy aging and improve Alzheimer's disease, etc. Currently, the methods for synthesizing the dibenzo-α-pyrone structure include the following Routes 1-5, mainly including palladium / copper-catalyzed tandem coupling, palladium-catalyzed C-H activation, coupling of biphenyl esters, oxidation of biphenyls, oxidation of 6H-benzochromenes, etc.: 。

[0003] The above synthesis methods have defects such as the use of toxic and expensive reagents, high-temperature conditions, long reaction time, long steps, etc., which bring troubles to the synthesis of dibenzo-α-pyrone compounds. Therefore, it is necessary to provide an environmentally friendly, simple and mild method for synthesizing dibenzo-α-pyrone compounds. Summary of the Invention

[0004] The present invention provides a method for synthesizing dibenzo-α-pyrone compounds and its application, so as to solve the problems of the existing synthesis methods such as being not environmentally friendly, having cumbersome steps, high reaction conditions and long reaction time.

[0005] According to the first aspect of the present invention, the present invention provides a method for synthesizing dibenzo-α-pyrone compounds, comprising the following steps: using a dibenzoylacetone compound as a raw material, reacting with an oxidant, a Lewis acid and an oxidation catalyst under the conditions of an organic solvent and room temperature.

[0006] It should be noted that room temperature generally refers to 20-25 °C.

[0007] The reaction mechanism of the synthesis method of a dibenzo-α-pyrone compound of the present invention is as follows: First, under the action of an oxidant, the dibenzylacetone compound undergoes a Baeyer-Villiger oxidation reaction to obtain a benzoic acid phenyl ester intermediate. Then, under the action of a Lewis acid and an oxidation catalyst, the benzoic acid phenyl ester intermediate undergoes an intramolecular Scholl oxidative coupling to obtain a dibenzo-α-pyrone compound. The starting material, the dibenzylacetone compound, of the synthesis method of the present invention is readily available. Based on the principles of Baeyer-Villiger oxidation and Scholl oxidative coupling, the dibenzo-α-pyrone compound is prepared by a one-pot method. The reaction is simple and the conditions are mild, providing a more efficient and green method for the preparation of bioactive substances such as urolithin a-c. The yield of the dibenzo-α-pyrone compound obtained by the synthesis method of the present invention can reach 76%.

[0008] In some specific embodiments, the dibenzo-α-pyrone compound has a structure shown in Formulas I-VIII: .

[0009] Furthermore, the dibenzylacetone compound has a structure shown in Formula MI: , MI, wherein R1, R2, R3, and R4 are each independently selected from H, halogen, alkyl, or alkoxy. Preferably, R1, R2, R3, and R4 are each independently selected from H, halogen, C1-C6 alkyl, or C1-C6 alkoxy; more preferably, R1, R2, R3, and R4 are each independently selected from H, halogen, C1-C3 alkyl, or C1-C3 alkoxy.

[0010] In some specific embodiments, the structure shown in Formula MI includes those shown in Formulas MI-1 to MI-7 as follows: .

[0011] Furthermore, the oxidant is one of m-chloroperbenzoic acid, hydrogen peroxide, or tert-butyl hydroperoxide. These oxidants can efficiently carry out the oxidation reaction at room temperature conditions without high temperature or high pressure conditions, greatly reducing the energy consumption. These oxidants show high selectivity in the Baeyer-Villiger oxidation reaction and can efficiently convert the ketone group into an ester group. In addition, these three oxidants have lower toxicity compared to traditional oxidants (such as chromic acid-based or halogen-based oxidants), which conforms to the concept of green chemistry, making the entire synthesis process more environmentally friendly and reducing environmental pollution.

[0012] To improve the reaction efficiency, further, the molar amount of the oxidant is 1 - 10 times the molar amount of the diphenylacetone compound. Optionally, the multiple of the molar amount of the oxidant to the molar amount of the diphenylacetone compound can be 1 time, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times or 10 times, etc. Of course, it can also be other values within the above range, which is not limited here.

[0013] Preferably, the molar amount of the oxidant is 1 - 2 times the molar amount of the diphenylacetone compound. By optimizing the molar amount of the oxidant, it can ensure that the ketone group in the substrate fully undergoes the Baeyer-Villiger oxidation reaction to generate sufficient ester intermediates. Too low an amount of the oxidant may lead to incomplete reactions, while an excessive amount of the oxidant may cause over-oxidation and generate unnecessary by-products. Controlling the amount of the oxidant within the range of 1 - 2 times can not only ensure complete reactions but also avoid over-oxidation, thereby improving the selectivity and yield of the target product.

[0014] Further, the Lewis acid is one of zinc sulfide, aluminum trichloride or iron bromide. These Lewis acids can promote the reaction at room temperature or lower temperatures, avoiding the energy consumption and side reaction problems brought about by high-temperature conditions. As Lewis acids, zinc sulfide, aluminum trichloride and iron bromide can effectively activate the reaction substrate, accelerate the Baeyer-Villiger oxidation and Scholl coupling reactions, and improve the reaction rate and yield.

[0015] To improve the reaction efficiency, further, the molar amount of the Lewis acid is 0.05 - 0.5 times the molar amount of the diphenylacetone compound. Optionally, the multiple of the molar amount of the Lewis acid to the molar amount of the diphenylacetone compound can be 0.05 times, 0.06 times, 0.07 times, 0.08 times, 0.09 times, 0.1 times, 0.15 times, 0.2 times, 0.25 times, 0.3 times, 0.35 times, 0.4 times, 0.45 times or 0.5 times, etc. Of course, it can also be other values within the above range, which is not limited here.

[0016] Preferably, the molar amount of the Lewis acid is 0.1 - 0.3 times the molar amount of the diphenylacetone compound. Experiments show that the Lewis acid can efficiently promote the reaction within the dosage range of 0.1 - 0.3 times. This dosage range can not only ensure catalytic activity but also avoid side reactions or overly complex reaction systems caused by excessive Lewis acid. Too little Lewis acid may make the reaction incomplete, while excessive Lewis acid may lead to multiple side reactions, reducing the selectivity and yield of the target product. By controlling the dosage within a suitable range, side reactions can be significantly reduced, and the purity and yield of the target product can be improved.

[0017] Furthermore, the oxidation catalyst is iron(III) meso-tetraphenylporphine chloride. Iron(III) meso-tetraphenylporphine chloride catalysts can efficiently promote Baeyer-Villiger oxidation reactions and Scholl oxidative coupling reactions, which are key steps in the synthesis of the dibenzo-α-pyrone skeleton structure. They have high catalytic activity, can rapidly initiate reactions under mild conditions, and significantly increase the reaction rate. Iron(III) meso-tetraphenylporphine chloride can catalyze reactions at room temperature or near room temperature without harsh conditions such as high temperature and high pressure, which not only reduces energy consumption but also decreases the occurrence of side reactions.

[0018] Preferably, the oxidation catalyst is one of iron(III) meso-tetraphenylporphine (CAS No.: 16009-13-5), iron(III) 5,10,15,20-tetraphenyl-21H,23H-porphine chloride (CAS No.: 16456-81-8), or iron(III) meso-tetrakis(4-carboxyphenyl)porphine chloride (CAS No.: 55266-17-6). By selecting different iron(III) meso-tetraphenylporphine chlorides, the reaction conditions can be further optimized to achieve the selective synthesis of different products.

[0019] To further improve the reaction effect. Furthermore, the molar amount of the oxidation catalyst is 0.05 - 0.5 times the molar amount of the diphenylacetone compound. Optionally, the multiple of the molar amount of the oxidation catalyst to the molar amount of the diphenylacetone compound can be 0.05 times, 0.06 times, 0.07 times, 0.08 times, 0.09 times, 0.1 times, 0.15 times, 0.2 times, 0.25 times, 0.3 times, 0.35 times, 0.4 times, 0.45 times, or 0.5 times, etc. Of course, it can also be other values within the above range, which are not limited herein.

[0020] Preferably, the molar amount of the oxidation catalyst is 0.08 - 0.15 times the molar amount of the diphenylacetone compound. Experiments show that the dosage range of 0.08 - 0.15 times can ensure that the catalyst fully plays its role in the reaction, effectively promoting the Baeyer-Villiger oxidation and Scholl coupling reactions, thus ensuring a high reaction rate and high yield. Too low a dosage may lead to a decrease in the reaction rate and a reduction in the yield; while too high a dosage may lead to an increase in side reactions and a decrease in the product purity.

[0021] Furthermore, the organic solvent is tetrahydrofuran, dichloromethane, or hexafluoroisopropyl ether. Different solvents have different physical and chemical properties (such as polarity, solubility, volatility, etc.). Selecting a suitable solvent according to specific reaction conditions and substrate characteristics can improve the reaction efficiency and product yield. Experiments have found that tetrahydrofuran, dichloromethane, or hexafluoroisopropyl ether can all exhibit good reaction performance.

[0022] Preferably, the organic solvent is hexafluoroisopropyl ether. Hexafluoroisopropyl ether is a solvent with excellent dissolving ability, which can well dissolve the benzophenone substrates, catalysts and oxidants in the reaction, ensuring the uniformity of the reaction system, thereby improving the reaction efficiency. Hexafluoroisopropyl ether has a relatively low boiling point (about 55 - 60 °C), and after the reaction is completed, the solvent can be quickly removed by simple rotary evaporation, simplifying the post-treatment steps and reducing energy consumption. Compared with traditional organic solvents (such as dichloromethane), hexafluoroisopropyl ether has lower toxicity and less harm to operators and the environment, meeting the requirements of green chemistry. Experiments have found that hexafluoroisopropyl ether exhibits higher reaction efficiency and product purity compared to tetrahydrofuran and dichloromethane.

[0023] Furthermore, the reaction time is 12 - 48 h. The time range of 12 - 48 h can ensure that the reaction proceeds fully, converting the reactants completely into the target product, and can avoid incomplete conversion due to too short reaction time or the formation of by-products due to too long reaction time, thereby improving the purity of the target product.

[0024] Furthermore, it also includes the following steps: washing, concentrating, and purifying the materials obtained from the reaction. The washing step can effectively remove the water-soluble impurities generated during the reaction or the unreacted raw materials, reducing the influence of impurities on the subsequent steps. The concentration and purification steps (such as column chromatography, recrystallization, etc.) can further separate and remove the by-products, ensuring the high purity of the target product.

[0025] In some specific embodiments, washing, concentrating, and purifying the materials obtained from the reaction specifically means that after the reaction is completed, distilled water is added to the reaction solution, then extracted with dichloromethane, the organic phases are combined, concentrated by a rotary evaporator, and the residue is purified by silica gel column chromatography.

[0026] According to the second aspect of the present invention, the present invention also provides the application of the above synthesis method in the synthesis of urolithin. The application method is: using the synthesis method to synthesize dibenzo-α-pyrone compounds, and then using the synthesized dibenzo-α-pyrone compounds as raw materials to obtain urolithin through a dealkylation reaction.

[0027] Furthermore, the dealkylation reaction is carried out by demethylation with boron tribromide.

[0028] It should be noted that urolithin includes urolithin a, urolithin b, and urolithin c, and their structural formulas are as follows: .

[0029] In some specific embodiments, the synthesis method of urolithin is as follows: at room temperature, dissolve the dibenzo-α-pyrone compound in an organic solvent (such as dichloromethane), and then add a dichloromethane solution of boron tribromide and react for 10-15 h. After the reaction is completed, add a saturated sodium bicarbonate solution to the reaction solution, then extract with dichloromethane, combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography.

[0030] Advantages of the present invention: The synthesis method of a dibenzo-α-pyrone compound provided by the present invention uses an easily available benzophenone compound as a raw material, and prepares the dibenzo-α-pyrone compound through Baeyer-Villiger oxidation and Scholl oxidative coupling by a one-pot method. The reaction is simple and the conditions are mild, providing a more efficient and green method for the preparation of bioactive substances such as urolithin a-c. Description of the drawings

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is the nuclear magnetic resonance hydrogen spectrum of the dibenzo-α-pyrone compound provided in Example 1 of the present invention.

[0033] Figure 2 It is the nuclear magnetic resonance carbon spectrum of the dibenzo-α-pyrone compound provided in Example 1 of the present invention.

[0034] Figure 3 It is the nuclear magnetic resonance hydrogen spectrum of the dibenzo-α-pyrone compound of formula I obtained in Example 16 of the present invention.

[0035] Figure 4 It is the nuclear magnetic resonance carbon spectrum of the dibenzo-α-pyrone compound of formula I obtained in Example 16 of the present invention.

[0036] Figure 5 It is the nuclear magnetic resonance hydrogen spectrum of the dibenzo-α-pyrone compound of formula VIII obtained in Example 16 of the present invention.

[0037] Figure 6 It is the nuclear magnetic resonance carbon spectrum of the dibenzo-α-pyrone compound of formula VIII obtained in Example 16 of the present invention.

[0038] Figure 7 It is the nuclear magnetic resonance hydrogen spectrum of the dibenzo-α-pyrone compound of formula II obtained in Example 17 of the present invention.

[0039] Figure 8 It is the carbon-13 NMR spectrum of the dibenzo-α-pyrone compound of Formula II obtained in Example 17 of the present invention.

[0040] Figure 9 It is the proton NMR spectrum of the dibenzo-α-pyrone compound of Formula IV obtained in Example 18 of the present invention.

[0041] Figure 10 It is the carbon-13 NMR spectrum of the dibenzo-α-pyrone compound of Formula IV obtained in Example 18 of the present invention.

[0042] Figure 11 It is the proton NMR spectrum of the dibenzo-α-pyrone compound of Formula V obtained in Example 19 of the present invention.

[0043] Figure 12 It is the carbon-13 NMR spectrum of the dibenzo-α-pyrone compound of Formula V obtained in Example 19 of the present invention.

[0044] Figure 13 It is the proton NMR spectrum of the dibenzo-α-pyrone compound of Formula VI obtained in Example 20 of the present invention.

[0045] Figure 14 It is the carbon-13 NMR spectrum of the dibenzo-α-pyrone compound of Formula VI obtained in Example 20 of the present invention.

[0046] Figure 15 It is the proton NMR spectrum of the dibenzo-α-pyrone compound of Formula VII obtained in Example 21 of the present invention.

[0047] Figure 16 It is the carbon-13 NMR spectrum of the dibenzo-α-pyrone compound of Formula VII obtained in Example 21 of the present invention.

[0048] Figure 17 It is the proton NMR spectrum of urolithin a obtained in Example 22 of the present invention.

[0049] Figure 18 It is the carbon-13 NMR spectrum of urolithin a obtained in Example 22 of the present invention.

[0050] Figure 19 It is the proton NMR spectrum of urolithin b obtained in Example 23 of the present invention.

[0051] Figure 20 It is the carbon-13 NMR spectrum of urolithin b obtained in Example 23 of the present invention.

[0052] Figure 21 It is the proton NMR spectrum of urolithin c obtained in Example 24 of the present invention.

[0053] Figure 22 It is the 13C NMR spectrum of urolithin C obtained in Example 24 of the present invention. Detailed implementation mode

[0054] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0055] The structural formulas of the dibenzo-α-pyrone compounds involved in the following examples are shown as Formulas I - VIII below: 。

[0056] Example 1 This example provides a method for synthesizing a dibenzo-α-pyrone compound, which specifically includes the following steps: At room temperature, into a 25-milliliter reaction flask equipped with a magnetic stir bar, substituted 3,3'-dimethoxydibenzoyl (0.4 mmol), m-chloroperbenzoic acid (0.4 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were successively added, and then 2 milliliters of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 milliliters of distilled water was added to the reaction solution, and then extracted with dichloromethane (5 milliliters * 3 times), the organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 42.5 mg of the target product with a yield of 42%.

[0057] As Figure 1 shown, the 1H NMR data of the dibenzo-α-pyrone compound of Formula III obtained are as follows: 1 H NMR (600 MHz, CDCl3) δ 7.93 (d, J J = 8.9 Hz, 1H), 7.87 (d, J J = 8.8 Hz,1H), 7.77 (d, J J = 2.8 Hz, 1H), 7.38 (dd, J J = 8.8, 2.8 Hz, 1H), 6.91 (dd, J J = 8.8,2.6 Hz, 1H), 6.87 (d, J J = 2.5 Hz, 1H), 3.93 (s, 3H), 3.88 (s, 3H).

[0058] As Figure 2 shown, the carbon-13 NMR data of the obtained compound of formula III are as follows: 13 C NMR (151 MHz, CDCl3) δ 161.83, 160.84, 159.33, 151.82, 128.86, 124.71, 123.33, 123.01, 121.15, 112.59, 111.48, 111.12, 101.72, 55.94, 55.86.

[0059] The high-resolution mass spectrometry data of the dibenzo-α-pyrone compound of formula III obtained are: HRMS (ESI): m / z calcd. C 15 H 13 O4 [M+H] + : 257.0828, found 257.0814.

[0060] Example 2 This example provides a method for synthesizing a dibenzo-α-pyrone compound, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, successively add substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL × 3 times), combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography to obtain 75 mg of the target product with a yield of 76%.

[0061] Example 3 This example provides a method for synthesizing a dibenzo-α-pyrone compound, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, successively add substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.8 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL × 3 times), combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography to obtain 75 mg of the target product with a yield of 76%.

[0062] Example 4 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, successively add substituted 3,3'-dimethoxydibenzoyl (0.4 mmol), m-chloroperbenzoic acid (1.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL * 3 times), combine the organic phases, concentrate with a rotary evaporator, and purify the residue by silica gel column chromatography to obtain 63.1 mg of the target product with a yield of 64%.

[0063] Example 5 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, successively add substituted 3,3'-dimethoxydibenzoyl (0.4 mmol), m-chloroperbenzoic acid (4 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL * 3 times), combine the organic phases, concentrate with a rotary evaporator, and purify the residue by silica gel column chromatography to obtain 25.6 mg of the target product with a yield of 26%.

[0064] Example 6 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, successively add substituted 3,3'-dimethoxydibenzoyl (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.02 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL * 3 times), combine the organic phases, concentrate with a rotary evaporator, and purify the residue by silica gel column chromatography to obtain 75 mg of the target product with a yield of 76%.

[0065] Example 7 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxydibenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.08 mmol) and zinc sulfide (0.08 mmol). Then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 75 mg of the target product with a yield of 76%.

[0066] Example 8 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxydibenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.2 mmol) and zinc sulfide (0.08 mmol). Then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 75 mg of the target product with a yield of 76%.

[0067] Example 9 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxydibenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.02 mmol). Then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 12.8 mg of the target product with a yield of 13%.

[0068] Example 10 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.04 mmol). Then, 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 56.2 mg of the target product with a yield of 57%.

[0069] Example 11 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.2 mmol). Then, 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 34.5 mg of the target product with a yield of 35%.

[0070] Example 12 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.4 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol). Then, 2 mL of tetrahydrofuran was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 42.5 mg of the target product with a yield of 42%.

[0071] Example 13 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.4 mmol), FeTCPP (0.04 mmol), and zinc sulfide (0.08 mmol). Then, 2 mL of dichloromethane was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated on a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 33.5 mg of the target product with a yield of 34%.

[0072] Example 14 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.4 mmol), FeTCPP (0.04 mmol), and zinc sulfide (0.08 mmol). Then, 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 12 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated on a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 26.4 mg of the target product with a yield of 25%.

[0073] Example 15 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, were successively added substituted 3,3'-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.4 mmol), FeTCPP (0.04 mmol), and zinc sulfide (0.08 mmol). Then, 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 48 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated on a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 32.7 mg of the target product with a yield of 32%.

[0074] Example 16 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, to a 25 mL reaction flask equipped with a magnetic stir bar, substituted 3-methoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were added successively. Then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated on a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 31 mg of the target product of formula I and 25.4 mg of formula VIII, with yields of 37.5% and 30%, respectively.

[0075] As Figure 3 shown, the 1H NMR data of the obtained compound of formula I are as follows: 1 H NMR (600 MHz, CDCl3) δ 8.39 (dd, J J = 8.0, 1.0 Hz, 1H), 8.03 (d, J J = 8.1Hz, 1H), 7.98 (d, J J = 8.8 Hz, 1H), 7.833 - 7.80 (m, 1H), 7.56 - 7.52 (m, 1H), 6.95 (dd, J J = 8.8, 2.6 Hz, 1H), 6.90 (d, J J = 2.5 Hz, 1H), 3.92 (s, 3H).

[0076] As Figure 4 shown, the 13C NMR data of the obtained compound of formula I are as follows: 13 C NMR (151 MHz, CDCl3) δ 161.70, 161.64, 152.78, 135.34, 135.05, 130.74, 127.91, 123.95, 121.25, 120.13, 112.64, 111.31, 101.77, 55.88.

[0077] The high-resolution mass spectrometry data of the obtained compound of formula I are as follows: HRMS (ESI): m / z calcd. C 13 H9O3[M+H] + : 213.0552, found 213.0524.

[0078] As Figure 5 shown, the 1H NMR data of the obtained compound of formula VIII are as follows: 1 1H NMR (600 MHz, CDCl3) δ 8.05 (d, J J = 8.8 Hz, 1H), 8.00 (dd, J J = 7.9, 1.4Hz, 1H), 7.82 (d, J J = 2.8 Hz, 1H), 7.43 (ddd, J J = 8.5, 7.2, 1.5 Hz, 1H), 7.41(dd, J J = 8.8, 2.8 Hz, 1H), 7.37 (dd, J J = 8.2, 1.1 Hz, 1H), 7.34 - 7.32 (m, 1H),3.94 (s, 3H).

[0079] As Figure 6 shown, the 13C NMR data of the obtained compound of formula VIII are as follows: 13 13C NMR (151 MHz, CDCl3) δ 161.37, 160.04, 150.45, 129.38, 128.17,124.61, 124.37, 123.49, 122.44, 122.23, 118.20, 117.64, 111.15, 55.84.

[0080] The high resolution mass spectrometry data of the obtained compound of formula VIII are as follows: HRMS (ESI): m / z calcd. C 13 H9O3[M+H] + : 213.0552, found 213.0558.

[0081] Example 17 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stir bar, substituted 3,4,3'-trimethoxybenzophenone (0.4 mmol), m-chloroperoxybenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were successively added, and then 2 mL of hexafluoroisopropyl ether was added. The reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then it was extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 158 mg of the target product of formula II, with a yield of 62%.

[0082] AsFigure 7 As shown, the 1H NMR data of the obtained compound of formula II are as follows: 1 H NMR (600 MHz, CDCl3) δ 8.40 (dd, J J = 7.9, 1.1 Hz, 1H), 8.00 (d, J J = 8.1Hz, 1H), 7.84 - 7.81 (m, 1H), 7.56 - 7.53 (m, 1H), 7.43 (s, 1H), 6.91 (s,1H), 4.03 (s, 3H), 3.98 (s, 3H).

[0083] As Figure 8 shown, the 13C NMR data of the obtained compound of formula II are as follows: 13 C NMR (151 MHz, CDCl3) δ 161.80, 151.56, 146.61, 146.53, 135.29,134.94, 130.85, 127.93, 121.21, 120.38, 110.15, 104.01, 100.98, 56.61, 56.45.

[0084] The high-resolution mass spectrometry data of the obtained compound of formula II are as follows: HRMS (ESI): m / z calcd. C 16 H 15 O5[M+H] + : 287.0926, found 287.0919.

[0085] Example 18 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stirrer, substituted 3-methoxy-4'-chlorobenzophenone (0.4 mmol), m-chloroperoxybenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were successively added, and then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then extracted with dichloromethane (5 mL × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 64 mg of the target product of formula IV, with a yield of 61.2%.

[0086] As Figure 9 shown, the 1H NMR data of the obtained compound of formula IV are as follows: 1 H NMR (600 MHz, CDCl3) δ 7.98 (d, J J = 8.8 Hz, 1H), 7.94 (d, J J = 2.3 Hz,1H), 7.81 (d, J J = 2.8 Hz, 1H), 7.41 (dd, J J = 8.8, 2.8 Hz, 1H), 7.37 (dd, J J = 8.7,2.4 Hz, 1H), 7.30 (d, J J = 8.7 Hz, 1H), 3.92 (s, 3H).

[0087] As Figure 10 shown, the 13C NMR data of the obtained compound of formula IV are as follows: 13 C NMR (151 MHz, CDCl3) δ 160.93, 160.71, 148.95, 130.21, 129.38,127.03, 124.58, 123.76, 122.68, 122.21, 119.71, 119.16, 111.57, 56.04.

[0088] The high-resolution mass spectrometry data of the obtained compound of formula IV are as follows: HRMS (ESI): m / z calcd. C 14 H 10 ClO3[M+H] + : 261.0328, found 261.0318.

[0089] Example 19 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stirrer, sequentially add substituted 3,4-dimethoxybenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol), then add 2 mL of hexafluoroisopropyl ether, and react at room temperature for 24 hours. After the reaction is completed, add 5 mL of distilled water to the reaction solution, then extract with dichloromethane (5 mL * 3 times), combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography to obtain 71 mg of the target product of formula V, with a yield of 69.5%.

[0090] As Figure 11 shown, the 1H NMR data of the obtained compound of formula V are as follows: 1 1H NMR (600 MHz, CDCl3) δ 8.40 (dd, J J = 7.9, 1.1 Hz, 1H), 8.00 (d, J J = 8.1Hz, 1H), 7.84 - 7.81 (m, 1H), 7.56 - 7.53 (m, 1H), 7.43 (s, 1H), 6.91 (s,1H), 4.03 (s, 3H), 3.98 (s, 3H).

[0091] As Figure 12 shown, the carbon NMR data of the obtained compound of formula V are as follows: 13 13C NMR (151 MHz, CDCl3) δ 161.80, 151.56, 146.61, 146.53, 135.29,134.94, 130.85, 127.93, 121.21, 120.38, 110.15, 104.01, 100.98, 56.61, 56.45.

[0092] The high-resolution mass spectrometry data of the obtained compound of formula V are as follows: HRMS (ESI): m / z calcd. C 15 H 13 O4[M+H] + : 257.0842, found 257.0814.

[0093] Example 20 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25-ml reaction flask equipped with a magnetic stir bar, substituted 4-chlorobenzophenone (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were successively added, and then 2 ml of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 ml of distilled water was added to the reaction solution, and then extracted with dichloromethane (5 ml × 3 times). The organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 71 mg of the target product of formula VI, with a yield of 77.5%.

[0094] As Figure 13 shown, the 1H NMR data of the obtained compound of formula VI are as follows: 11H NMR (600 MHz, CDCl3) δ 8.41 (dd, J J = 7.9, 1.0 Hz, 1H), 8.06 (d, J J = 8.1Hz, 1H), 8.02 (d, J J = 2.4 Hz, 1H), 7.87 - 7.85 (m, 1H), 7.65 - 7.63 (m, 1H),7.43 (dd, J J = 8.8, 2.4 Hz, 1H), 7.32 (d, J J = 8.7 Hz, 1H).

[0095] As Figure 14 shown, the 13C NMR data of the obtained compound of Formula VI are as follows: 13 13C NMR (151 MHz, CDCl3) δ 160.78, 149.82, 135.25, 133.73, 130.90,130.53, 130.21, 129.79, 122.78, 121.96, 121.38, 119.52, 119.37.

[0096] The high-resolution mass spectrometry data of the obtained compound of Formula VI are as follows: HRMS (ESI): m / z calcd. C 15 H 13 O4[M+H] + : 231.0235, found 231.0213.

[0097] Example 21 This example provides a method for synthesizing dibenzo-α-pyrone compounds, which specifically includes the following steps: At room temperature, into a 25 mL reaction flask equipped with a magnetic stirrer, the substituted 3-methyldibenzoyl (0.4 mmol), m-chloroperbenzoic acid (0.6 mmol), FeTCPP (0.04 mmol) and zinc sulfide (0.08 mmol) were successively added, and then 2 mL of hexafluoroisopropyl ether was added, and the reaction was carried out at room temperature for 24 hours. After the reaction was completed, 5 mL of distilled water was added to the reaction solution, and then extracted with dichloromethane (5 mL × 3 times), the organic phases were combined, concentrated by a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain 50 mg of the target product of Formula VII, with a yield of 59.6%.

[0098] As Figure 15 shown, the 1H NMR data of the obtained compound of Formula VII are as follows: 11H NMR (600 MHz, CDCl3) δ 8.22 (d, J J = 0.4 Hz, 1H), 8.05 (dd, J J = 12.7, 4.8 Hz, 2H), 7.67 - 7.64 (m, 1H), 7.48 - 7.45 (m, 1H), 7.37 (dd, J J = 8.2, 1.1 Hz, 1H), 7.33 (ddd, J J = 31.5, 18.3, 14.3 Hz, 1H), 2.51 (s, 3H).

[0099] As Figure 16 shown, the 13C NMR data of the obtained compound of formula VII are as follows: 13 13C NMR (151 MHz, CDCl3) δ 161.63, 151.18, 139.44, 136.28, 132.42, 130.59, 130.11, 124.67, 122.72, 121.88, 121.26, 118.39, 117.90, 21.51.

[0100] The high-resolution mass spectrometry data of the obtained compound of formula VII are as follows: HRMS (ESI): m / z calcd. C 15 H 13 O4 [M+H] + : 211.0755, found 211.0759.

[0101] Example 22 This example provides a method for synthesizing urolithin a, which specifically includes the following steps: At room temperature, add the dibenzo-α-pyrone compound of formula III (2 mmol) to a 25 mL reaction flask equipped with a magnetic stirrer, dissolve it with 10 mL of dichloromethane, then add 3 mL of a 1 mol / L boron tribromide dichloromethane solution, and react at room temperature for 12 hours. After the reaction is completed, add 10 mL of saturated sodium bicarbonate solution to the reaction solution, then extract with dichloromethane (10 mL × 3 times), combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography to obtain 300 mg of urolithin a with a yield of 68%.

[0102] As Figure 17 shown, the 1H NMR data of the obtained urolithin a are as follows: 11H NMR (600 MHz, DMSO) δ 10.23 (s, 2H), 8.08 (d, J J = 8.8 Hz, 1H), 7.99(d, J J = 8.8 Hz, 1H), 7.51 (d, J J = 2.7 Hz, 1H), 7.30 (dd, J J = 8.7, 2.7 Hz, 1H), 6.80(dd, J J = 8.7, 2.4 Hz, 1H), 6.72 (d, J J = 2.4 Hz, 1H).

[0103] As Figure 18 shown, the 13C NMR data of the obtained urolithin a are as follows: 13 13C NMR (151 MHz, DMSO) δ 160.72, 158.66, 157.06, 150.98, 127.01, 124.24, 123.86, 123.63, 120.24, 113.61, 113.11, 109.90, 102.94.

[0104] The high-resolution mass spectrometry data of the obtained urolithin a are as follows: HRMS (ESI): m / z calcd. C 13 H9O4[M+H] + : 229.0523, found 229.0501.

[0105] Example 23 This example provides a method for synthesizing urolithin b, which specifically includes the following steps: At room temperature, add the dibenzo-α-pyrone compound of formula I (2 mmol) to a 25 mL reaction flask equipped with a magnetic stirrer, dissolve it in 10 mL of dichloromethane, then add 3 mL of a 1 mol / L boron tribromide dichloromethane solution, and react at room temperature for 12 hours. After the reaction is completed, add 10 mL of saturated sodium bicarbonate solution to the reaction solution, then extract with dichloromethane (10 mL * 3 times), combine the organic phases, concentrate on a rotary evaporator, and purify the residue by silica gel column chromatography to obtain 371 mg of urolithin b with a yield of 87.5%.

[0106] As Figure 19 shown, the 1H NMR data of the obtained urolithin b are as follows: 11H NMR (600 MHz, DMSO) δ 10.37 (s, 1H), 8.24 (d, J J = 6.9 Hz, 1H), 8.16(dd, J J = 14.6, 7.3 Hz, 2H), 7.87 (dd, J J = 10.9, 7.3 Hz, 1H), 7.55 (td, J J = 7.6, 3.1Hz, 1H), 6.84 (d, J J = 8.7 Hz, 1H), 6.75 (s, 1H).

[0107] As Figure 20 shown, the 13C NMR data of the obtained urolithin b are as follows: 13 13C NMR (151 MHz, DMSO) δ 160.64, 159.91, 152.14, 135.30, 135.12, 129.70, 127.67, 124.86, 121.67, 118.96, 113.18, 109.38, 102.96.

[0108] The high-resolution mass spectrometry data of the obtained urolithin b are as follows: HRMS (ESI): m / z calcd. C 13 H9O3[M+H] + : 213.0542, found 213.0552.

[0109] Example 24 This example provides a method for synthesizing urolithin c, which specifically includes the following steps: At room temperature, add the dibenzo-α-pyrone compound of formula II (2 mmol) to a 25-ml reaction flask equipped with a magnetic stir bar, dissolve it in 10 ml of dichloromethane, then add 3 ml of a 1 mol / L boron tribromide dichloromethane solution, and react at room temperature for 12 hours. After the reaction is completed, add 10 ml of saturated sodium bicarbonate solution to the reaction solution, then extract with dichloromethane (10 ml × 3 times), combine the organic phases, concentrate by rotary evaporator, and purify the residue by silica gel column chromatography to obtain 268.4 mg of urolithin c with a yield of 55.2%.

[0110] As Figure 21 shown, the 1H NMR data of the obtained urolithin c are as follows: 1 1H NMR (600 MHz, DMSO) δ 10.15 (s, 3H), 7.85 (d,J = 8.8 Hz, 1H), 7.49(s, 1H), 7.44 (s, 1H), 6.79 (dd, J = 8.7, 2.4 Hz, 1H), 6.69 (d, J = 2.4 Hz, 1H).

[0111] As Figure 22 shown, the carbon NMR data of the obtained urolithin c are as follows: 13 C NMR (151 MHz, DMSO) δ 160.35, 158.61, 153.49, 151.48, 146.16, 129.21, 123.79, 114.19, 112.89, 110.87, 109.81, 106.88, 102.80.

[0112] The high-resolution mass spectrometry data of the obtained urolithin c are as follows: HRMS (ESI): m / z calcd. C 13 H9O5[M+H] + : 245.0461, found 245.0450.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synthesizing dibenzo-α-pyrone compounds, characterized in that, It includes the following steps: Using a diphenylacetone compound as a raw material, reacting with an oxidant, a Lewis acid, and an oxidation catalyst under organic solvent and room temperature conditions.

2. The synthesis method according to claim 1, characterized in that, The diphenylacetone compound has a structure shown in formula MI: , MI, wherein R1, R2, R3 and R4 are each independently selected from H, halogen, alkyl or alkoxy.

3. The synthesis method according to claim 1 or 2, characterized in that, The oxidant is one of meta-chloroperbenzoic acid, hydrogen peroxide, or tert-butyl hydroperoxide.

4. The synthesis method according to any one of claims 1-3, characterized in that, The molar amount of the oxidant used is 1 - 10 times, preferably 1 - 2 times, the molar amount of the diphenylacetone compound used.

5. The synthesis method according to any one of claims 1-4, characterized in that, The Lewis acid is one of zinc sulfide, aluminum trichloride, or iron bromide; and / or, the molar amount of the Lewis acid used is 0.05 - 0.5 times, preferably 0.1 - 0.3 times, the molar amount of the diphenylacetone compound used.

6. The synthesis method according to any one of claims 1-5, characterized in that, The oxidation catalyst is iron(III) meso-tetraphenylporphine chloride, preferably one of iron porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphine iron(III) chloride, or meso-tetrakis(4-carboxyphenyl)porphine iron(III) chloride; and / or, the molar amount of the oxidation catalyst used is 0.05 - 0.5 times, preferably 0.08 - 0.15 times, the molar amount of the diphenylacetone compound used.

7. The synthesis method according to any one of claims 1-6, characterized in that, The organic solvent is tetrahydrofuran, dichloromethane, or hexafluoroisopropyl ether, preferably hexafluoroisopropyl ether.

8. The synthesis method according to any one of claims 1 to 7, characterized in that, The reaction time is 12 - 48 h.

9. The synthesis method according to any one of claims 1-8, characterized in that, It further includes the following steps: washing, concentrating, and purifying the reaction product.

10. Use of the synthesis method according to any one of claims 1-9 in the synthesis of urolithin, characterized in that, The application method is: synthesizing a dibenzo-α-pyrone compound by the said synthesis method, and then obtaining urolithin by a dealkylation reaction using the synthesized dibenzo-α-pyrone compound as a raw material.

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