Preparation method of gamma-pyrone compound

Abstract

The invention discloses a preparation method of a gamma-pyrone compound, which comprises the following steps: by taking a dibromo ketene compound as shown in a chemical structural general formula (I) and a non-terminal alkyne compound as shown in a structural general formula (II) as raw materials, reacting in an organic solvent at 100-120 DEG C for 10-24 hours under the action of a catalyst and an additive, and separating to obtain the gamma-pyrone compound. The structural general formula of the gamma-pyrone compound is shown as (III). The synthesis process of the dibromo ketene compound and the non-terminal alkyne compound used as the raw materials is simple to operate, easy to prepare, high in conversion rate and wide in substrate application range; the gamma-pyrone compound is successfully prepared by taking the dibromo ketene compound and the non-terminal alkyne compound as raw materials, and the method has the characteristics of simple steps, easiness in operation, low cost, environment friendliness, high atom economy and high yield. The gamma-pyrone compounds are widely distributed in biological and pharmaceutical active molecules, so that the gamma-pyrone compounds have a wide application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and particularly relates to a method for preparing a gamma-pyrone compound. Background Art

[0002] Pyrone, as an important unsaturated oxygen-containing six-membered heterocycle, is extremely common in natural products and has attracted much attention due to its unique chemical structure and diverse pharmacological effects. γ-Pyrone represents a very valuable building block, and its lactone structure gives it unique chemical properties and application value. In natural products, γ-pyrone is widespread and diverse. For example, compounds such as onchitriols I and II, ceryrcene A, and N-Acetylaureothamine all contain this characteristic structure. In addition to its medicinal value, γ-pyrone also exhibits unique optical properties due to its fully conjugated structure. This structure makes some γ-pyrone compounds have photosensitivity, which provides possibilities for the development of fluorescent probes, photochromic materials and other fields.

[0003] Based on the various biological activities and material properties exhibited by the pyrone skeleton, many researchers are committed to developing simple and economical methods to construct the complex skeleton of γ-pyrone compounds. At present, the main methods for constructing γ-pyrone include: (1) cyclization of 1,3,5-tricarbonyl compounds; (2) condensation of 1,3-dicarbonyl derivatives or enaminones; (3) [4+2] cyclization of acetylenone with vinyl ether; (4) TsOH-mediated electrophilic cyclization of diacetylenone; (5) [3+3] cyclization of α,β-unsaturated alkynyl carboxylic acids and 1,3-dicarbonyl compounds as reaction substrates under the synergistic mediation of 4-(dimethylamino)pyridine / Lewis acid. In addition, metal-catalyzed cyclization is also an efficient method for synthesizing γ-pyrone derivatives, and the metal catalysts involved are rhodium, scandium, gold, palladium, and copper. However, these methods still have certain limitations because the main precursors (raw materials) usually need to be prepared through multi-step synthesis, which not only reduces the atom economy but also significantly affects the yield of the final product. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide a method for preparing γ-pyrone compounds. The method has the characteristics of simple steps, easy operation, green environmental protection, low cost, high atom economy, high yield, etc.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing a γ-pyrone compound, comprising the following steps: using dibromophenone compounds and non-terminal acetylene compounds as raw materials, reacting in an organic solvent at 100 to 120° C. for 10 to 24 hours under the action of a catalyst and an additive, to obtain a γ-pyrone compound as shown in the general structural formula (III);

[0007]

[0008] Among them, R 1 Any one selected from H, C1-C3 alkyl, halogen, C1-C4 alkoxy, C1-C3 ester, aromatic, heterocyclic, R 2 and R 3 The same or different groups are selected from any one of a C1-C3 alkyl group, a phenyl group, an aromatic group having a C1-C3 alkyl substituent, an aromatic group having a halogen substituent, and a heterocyclic group.

[0009] Preferably, the molar ratio of the catalyst to the dibromophenone compound is 0.01-0.05:1.

[0010] Preferably, the molar ratio of the additive to the dibromophenone compound is 0.01-0.05:1.

[0011] Preferably, the molar ratio of the non-terminal acetylene compound to the dibromoketene compound is 1.0-1.5:1.0.

[0012] Preferably, the dibromoketone compound is selected from any one of 3,3-dibromo-1-phenylprop-2-ene-1-one, 3,3-dibromo-1-(p-tolyl)prop-2-ene-1-one, 3,3-dibromo-1-(m-tolyl)prop-2-ene-1-one, 3,3-dibromo-1-(4-fluorophenyl)prop-2-ene-1-one, 3,3-dibromo-1-(4-methoxyphenyl)prop-2-ene-1-one, 4-(3,3-dibromoacryloyl)benzoic acid methyl ester, 1-([1,1'-biphenyl]-4-yl)-3,3-dibromopropyl-2-ene-1-one and 3,3-dibromo-1-(thiophene-2-yl)prop-2-ene-1-one.

[0013] Preferably, the non-terminal acetylene compound is selected from any one of diphenylacetylene, 2-butyne, 1,2-di-m-tolueneacetylene, 1,2-bis(4-fluorophenyl)acetylene, 1,2-di(thiophen-2-yl)acetylene, and prop-1-yn-1-ylbenzene.

[0014] Preferably, the catalyst is any one of dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer, tri(triphenylphosphine)carbonyldihydroruthenium(II), ruthenium trichloride, and dichloro(p-methylisopropylbenzene)ruthenium(II) dimer.

[0015] Preferably, the additive is any one of cupric acetate, cupric chloride, cuprous bromide, cupric trifluoroacetate, and potassium persulfate.

[0016] Preferably, the organic solvent is any one of methanol, ethanol, acetonitrile and ethylene glycol.

[0017] Preferably, the method further comprises the step of purifying the reaction product by thin layer chromatography after the reaction is completed, wherein the developing solvent system used is petroleum ether / ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 8-3:1.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The synthesis process of the raw materials dibromophenone compounds and non-terminal acetylene compounds used in the method of the present invention is simple to operate, easy to prepare, high in conversion rate, and has a wide range of substrate applications; the method of the present invention has the characteristics of relatively mild reaction conditions, simple and easy to operate steps, low cost (low in price of the catalyst used), few reaction by-products, green and environmental protection, high atom economy and high yield. Since γ-pyrone compounds are widely distributed in biological and pharmaceutically active molecules (such as inhibitors, anti-tumor drugs), they have broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A synthetic route diagram of a γ-pyrone compound provided by the present invention;

[0022] Figure 2 is the structural formula of a representative example of a dibromophenone compound;

[0023] Figure 3 The structural formulas of representative examples of non-terminal acetylenic compounds are shown below;

[0024] Figure 4 is the structural formula of a representative example of γ-pyrone compounds;

[0025] Figure 5 is the NMR spectrum of compound 3a-1 prepared in Example 1;

[0026] Figure 6 This is the carbon spectrum of compound 3a-1 prepared in Example 1. DETAILED DESCRIPTION

[0027] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are provided to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.

[0028] Example 1

[0029] Reference Figure 1-4 , compound 3a-1 was prepared according to the synthetic route of γ-pyrone compounds.

[0030] 3,3-Dibromo-1-phenylprop-2-en-1-one (compound 1-1, chemical structure shown in Figure 2 , 0.1mmol, 0.0289g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper acetate (0.03mmol, 0.0005g), diphenylacetylene (compound 2-1, chemical structure see Figure 3 , 0.15mmol, 0.0267g) and methanol (2.0mL), stirred at 120℃ for 24h, monitored by TLC, and after the reaction was completed, the product was separated and purified by thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 5:1), and the product was a white solid substance, namely compound 3a-1, with a yield of 78%. Its NMR spectrum and carbon spectrum results are shown in Figure 5 and Figure 6 .

[0031] 1 H NMR (400MHz, CDCl3) δ7.85-7.78 (m, 2H), 7.48 (d, J = 5.1Hz, 3H), 7.31 (dd, J = 11. 2,7.5Hz,3H),7.24(dt,J=10.3,4.8Hz,5H),7.18(d,J=7.5Hz,2H),6.95(s,1H). 13 CNMR(101MHz,CDCl3)δ179.10,162.81,161.14,132.76,132.25,131.39,1 30.88,130.05,129.38,129.14,128.39,128.25,127.91,125.90,110.90.

[0032] Example 2

[0033] 3,3-Dibromo-1-(p-tolyl)prop-2-en-1-one (compound 1-2, chemical structure shown in Figure 2 , 0.1mmol, 0.0304g), cuprous bromide (0.03mmol, 0.0010g), tris(triphenylphosphine)carbonyldihydroruthenium(II) (5mol%, 0.0003g), prop-1-yn-1-ylbenzene (compound 2-5, chemical structure see Figure 3 , 0.12mmol, 0.0139g) and acetonitrile (1.0mL), stirred at 100℃ for 10h, and after the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system is petroleum ether / ethyl acetate, the volume of the two is 5:1) was used to separate and purify the product, which is a white solid substance, namely compound 3a-2, with a yield of 61%.

[0034] 1 H NMR (400MHz, CDCl3) δ7.81(dd,J=7.2,2.0Hz,2H),7.65(dd,J=6.4,2.9Hz,2H),7.58-7.46(m,6H),6.87(s,1H),3.86(s,3H).2.14(s,3H). 13 C NMR (101MHz, CDCl3) δ180.73,162.82,160.70,132.86,131.52,131.22,130.21,130.12,129. 04,128.91,128.58,128.47,125.80,125.81,125.73,121.92,110.82,109.34,29.73,21.53.

[0035] Example 3

[0036] 3,3-Dibromo-1-(m-tolyl)prop-2-en-1-one (compound 1-3, chemical structure shown in Figure 2 , 0.1mmol, 0.0304g), ruthenium trichloride (5mol%, 0.0001g), copper chloride (0.01mmol, 0.0002g), add 1,2-dimethylbenzene acetylene (compound 2-2, chemical structure see Figure 3 , 0.15mmol, 0.031g) and ethylene glycol (1.0mL), stirred at 120℃ for 24h, and monitored by TLC. After the reaction was completed, thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 3:1) was used to separate and purify the product. The product was a white solid substance, namely compound 3a-3, with a yield of 52%.

[0037] 1H NMR (400MHz, CDCl3) δ7.87 (dd, J=6.5, 3.1Hz, 2H), 7.52 (dd, J=5.1, 1.8Hz, 3H), 7.20 (d, J=8.0Hz, 2H), 7.1 6(d,J=8.9Hz,3H),7.10(d,J=11.5Hz,2H),6.97(d,J=6.7Hz,2H),2.44(s,3H),2.31(s,3H),2.28(s,3H). 13 C NMR (101MHz, CDCl3) δ179.25,162.67,137.87,137.84,132.67,132.23,131.48,131.36,131.32,130.76, 129.83,129.13,128.68,128.26,128.01,127.81,126.69,126.60,125.90,110.87,21.58,21.51,21.46.

[0038] Example 4

[0039] 3,3-Dibromo-1-(4-fluorophenyl)prop-2-en-1-one (compound 1-4, chemical structure shown in Figure 2 , 0.1mmol, 0.0031g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper acetate (0.05mmol, 0.0009g), diphenylacetylene (compound 2-1, 0.15mmol, 0.0267g) and ethanol (1.0mL) were added, and the reaction was stirred at 120°C for 24h. After the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 8:1) was used to separate and purify the product. The product was a white solid substance, namely compound 3a-4, with a yield of 71%.

[0040] 1 H NMR (400MHz, CDCl3) δ7.86 (dd, J=8.7, 5.2Hz, 2H), 7.38-7.33 (m, 3H), 7.30 (t, J=5.9Hz, 5H), 7.24-7.18 (m, 4H), 6.93 (s, 1H). 13C NMR(101MHz, CDCl3)δ178.90,161.83(d,J=2.9Hz),161.08,132.65,132.08,130.91,130.83(2C),130.09,129.33(2C), 128.39(2C),128.27(2C),128.11,128.02,127.94,127.62(d,J=3.2Hz),126.56(d,J=2.1Hz),116.50,116.28,110.67. 19 F NMR(376MHz,Chloroform-d)δ-107.826.

[0041] Example 5

[0042] 3,3-dibromo-1-(4-methoxyphenyl)prop-2-en-1-one (compound 1-5, chemical structure shown in Figure 2 , 0.1mmol, 0.032g), tris(triphenylphosphine)carbonyldihydroruthenium(II) (5mol%, 0.0003g), copper acetate (0.05mmol, 0.0009g), diphenylacetylene (compound 2-1, 0.12mmol, 0.0214g) and methanol (1.0mL) were added, and the reaction was stirred at 110°C for 24h. After the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 3:1) was used to separate and purify the product. The product was a white solid substance, namely compound 3a-5, with a yield of 66%.

[0043] 1 H NMR(400MHz, CDCl3)δ7.81(d,J=8.9Hz,2H),7.39-7.34(m,3H),7.30(q,J=6.6,6.1H z,5H),7.21(dd,J=7.5,1.8Hz,2H),7.02(d,J=8.9Hz,2H),6.90(s,1H),3.89(s,3H). 13 C NMR (101MHz, CDCl3) δ179.13,162.86,162.17,160.84,132.87,132.36,130.90(2C),129. 95,129.37,128.37,128.21,127.84,127.57(2C),126.25,123.70,114.54,109.44,55.53.

[0044] Example 6

[0045] Add 4-(3,3-dibromoacryloyl)benzoic acid methyl ester (compound 1-6, chemical structure shown in Figure 2 , 0.1mmol, 0.035g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (2mol%, 0.0001g), copper acetate (0.05mmol, 0.0009g), diphenylacetylene (compound 2-1, 0.15mmol, 0.0267g) and methanol (1.0mL) were added, and the reaction was stirred at 120°C for 24h. After the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 5:1) was used to separate and purify the product. The product was a white solid substance, namely compound 3a-6, with a yield of 56%.

[0046] 1 H NMR(400MHz, CDCl3)δ8.18(d,J=8.5Hz,2H),7.93(d,J=8.5Hz,2H),7.40-7.34(m, 3H),7.31(d,J=4.7Hz,5H),7.22(dd,J=7.4,2.0Hz,2H),7.05(s,1H),3.97(s,3H). 13 CNMR (101MHz, CDCl3) δ180.93,178.85,166.20,161.49,138.01,132.55,132.50,130. 82,130.31,130.21,128.44,128.33,128.03,125.82,124.68,124.48,112.11,52.52.

[0047] Example 7

[0048] 1-([1,1'-biphenyl]-4-yl)-3,3-dibromopropyl-2-en-1-one (compound 1-7, chemical structure shown in Figure 2 , 0.1mmol, 0.036g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper acetate (0.05mmol, 0.0009g), diphenylacetylene (compound 2-1, 0.10mmol, 0.0178g) and methanol (1.0mL) were added, and the reaction was stirred at 120°C for 20h. After the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 3:1) was used to separate and purify the product. The product was a white solid substance, namely compound 3a-7, with a yield of 59%.

[0049] 1H NMR (400MHz, CDCl3) δ7.94 (d, J = 7.8Hz, 2H), 7.75 (d, J = 7.7Hz, 2H), 7.66 (d, J = 8.1Hz, 2H), 7.50 (t, J = 7. 6Hz,2H),7.40(dt,J=13.7,7.4Hz,4H),7.36-7.28(m,5H),7.24(d,J=7.7Hz,2H),7.03(d,J=1.2Hz,1H). 13 C NMR (101MHz, CDCl3) δ179.05,162.55,161.07,144.16,144.06,139.86,139.77,132.77,132.20,130.87(2C),130.11, 130.06,129.39(2C),129.03(2C),128.40,128.26,128.20,127.92,127.75,127.15(2C),126.59,126.36(2C),110.55.

[0050] Example 8

[0051] 3,3-Dibromo-1-(thiophen-2-yl)prop-2-en-1-one (compound 1-8, chemical structure shown in Figure 2 , 0.1mmol, 0.029g), ruthenium trichloride (5mol%, 0.0001g), copper acetate (0.05mmol, 0.0009g), diphenylacetylene (compound 2-1, 0.12mmol, 0.0214g) and acetonitrile (1.0mL) were added, and the reaction was stirred at 110°C for 20h. After the reaction was completed by TLC monitoring, thin layer chromatography (developing solvent system is petroleum ether / ethyl acetate, the volume of the two is 3:1) was used to separate and purify the product. The product was a brown solid substance, namely compound 3a-8, with a yield of 23%.

[0052] 1 H NMR (400MHz, CDCl3) δ7.64(dd,J=3.7,1.2Hz,1H),7.55(dd,J=5.0,1.2Hz,1H),7.36(d,J=2.1Hz,1H),7.35-7.33(m,2H),7.31(d,J=1.6H z,1H),7.30(d,J=2.0Hz,2H),7.29(d,J=1.1Hz,1H),7.27(t,J=1.4Hz,1H),7.24-7.20(m,2H),7.18(dd,J=5.0,3.7Hz,1H),6.83(s,1H). 13C NMR (101MHz, CDCl3) δ178.62,158.62,134.70,132.47,132.13,130.82(2C),130.10,129 .72,129.50,129.35(2C),128.49,128.41,128.22(2C),127.95,127.80,126.48,109.40.

[0053] Example 9

[0054] 3,3-dibromo-1-phenylprop-2-en-1-one (compound 1-1, 0.1mmol, 0.029g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper trifluoroacetate (0.03mmol, 0.0009g) were added to a 10mL Shrek tube in sequence, and 1,2-di(thiophen-2-yl)acetylene (compound 2-4, 0.12mmol, 0.0228g) and methanol (1.0mL) were added. The reaction was stirred at 120°C for 24h. After the reaction was completed by monitoring by TLC, the product was separated and purified by thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 3:1). The product was a brown solid substance, namely compound 3a-9, with a yield of 54%.

[0055] 1 H NMR (400MHz, CDCl3) δ7.91-7.86(m,2H),7.58-7.52(m,4H),7.47(dd,J=5.0,1.2Hz,1H),7.17(dd,J=5 .2,3.5Hz,1H),7.08(d,J=1.2Hz,1H),7.07(d,J=1.2Hz,1H),7.02(dd,J=5.0,3.8Hz,1H),6.90(s,1H). 13 C NMR (101MHz, CDCl3) δ178.76,162.39,156.97,134.20,132.01,131.54,131.14,131 .07,130.88,129.64,129.22,128.49,127.82,127.57,125.92(2C),117.97,110.09.

[0056] Example 10

[0057] 3,3-dibromo-1-phenylprop-2-en-1-one (compound 1-1, 0.1mmol, 0.029g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper acetate (0.05mmol, 0.0009g), 2-butyne (compound 2-6, 0.15mmol, 0.0008g) and methanol (1.0mL) were added to a 10mL Shrek tube in sequence, and the reaction was stirred at 120°C for 24h. After the reaction was completed by monitoring by TLC, the product was separated and purified by thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 6:1). The product was a white solid substance, namely compound 3a-10, with a yield of 8%.

[0058] 1 H NMR (400MHz, CDCl3) δ7.76 (dd, J = 6.4, 2.9Hz, 2H), 7.54-7.43 (m, 3H), 6.73 (s, 1H), 2.41 (s, 3H), 2.00 (s, 3H). 13 C NMR (101MHz, CDCl3) δ180.02,162.44,161.14,131.05,131.04,128.99(2C),125.64(2C),109.47,29.73,17.83.

[0059] Embodiment 11

[0060] To a 10 mL Shrek tube, 3,3-dibromo-1-phenylprop-2-en-1-one (compound 1-1, 0.1 mmol, 0.029 g), dichloro(p-methylisopropylbenzene)ruthenium(II) dimer (5 mol%, 0.0003 g), copper acetate (0.05 mmol, 0.0009 g), prop-1-yn-1-ylbenzene (compound 2-5, 0.15 mmol, 0.0174 g) and methanol (1.0 mL) were added in sequence, and the reaction was stirred at 120°C for 24 h. After the reaction was completed by monitoring by TLC, the product was separated and purified by thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 3:1). The product was a white solid substance, namely compound 3a-11, with a yield of 81%.

[0061] 1 H NMR (400MHz, CDCl3) δ7.81 (dd, J=7.2, 2.0Hz, 2H), 7.65 (dd, J=6.4, 2.9Hz, 2H), 7.58-7.46 (m, 6H), 6.87 (s, 1H), 2.14 (s, 3H). 13C NMR (101MHz, CDCl3) δ180.73,162.82,160.70,132.86,131.52,131.22,130.21,130.12,129. 04,128.91,128.58,128.47,125.80,125.81,125.73,121.92,110.82,109.34,29.73,11.53.

[0062] Example 12

[0063] 3,3-Dibromo-1-phenylprop-2-en-1-one (compound 1-1, 0.1mmol, 0.029g), dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer (5mol%, 0.0003g), copper acetate (0.05mmol, 0.0009g), 1,2-bis(4-fluorophenyl)acetylene (compound 2-3, 0.12mmol, 0.031g) and ethanol (1.0mL) were added to a 10mL Shrek tube in sequence, and the reaction was stirred at 120°C for 20h. After the reaction was completed by monitoring by TLC, the product was separated and purified by thin layer chromatography (developing solvent system was petroleum ether / ethyl acetate, the volume of the two was 8:1). The product was a white solid substance, namely compound 3a-12, with a yield of 65%.

[0064] 1 H NMR (400MHz, CDCl3) δ7.84(dd,J=7.5,1.9Hz,2H),7.57-7.49(m,3H),7.40-7.33(m,2H),7.19(dd,J=8.6,5.5Hz,2H),7.07-6.95(m,5H). 13 C NMR (101MHz, CDCl3) δ178.80,178.80,164.73,163.69,162.97(dd,J=250.0,101.8Hz),161.23,160.24,132.61(d,J=8.1 Hz),131.54,131.52,131.43,131.12,129.03(2C)129.20,128.66(d,J=3.4Hz),125.89,125.89,115.78,115.57,110.83. 19 F NMR(376MHz,Chloroform-d)δ-108.86,-113.50.

[0065] The present invention is not limited to the above-mentioned specific implementation modes. Various changes made by ordinary technicians in this field based on the above-mentioned concepts without creative work are all within the protection scope of the present invention.

Claims

1. A method for preparing a γ-pyrone compound, characterized in that: The method comprises the following steps: using dibromophenones and non-terminal acetylene compounds as raw materials, reacting in an organic solvent at 100 to 120° C. for 10 to 24 hours under the action of a catalyst and an additive, to obtain a γ-pyrone compound as shown in the general structural formula (III): Among them, R 1 Any one selected from H, C1-C3 alkyl, halogen, C1-C4 alkoxy, C1-C3 ester, aromatic, heterocyclic, R 2 and R 3 The same or different groups are selected from any one of a C1-C3 alkyl group, a phenyl group, an aromatic group having a C1-C3 alkyl substituent, an aromatic group having a halogen substituent, and a heterocyclic group.

2. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The molar ratio of the catalyst to the dibromophenone compound is 0.01-0.05:

1.

3. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The molar ratio of the additive to the dibromophenone compound is 0.01-0.05:

1.

4. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The molar ratio of the non-terminal acetylene compound to the dibromoketene compound is 1.0-1.5:1.

0.

5. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The dibromoketone compound is selected from any one of 3,3-dibromo-1-phenylprop-2-ene-1-one, 3,3-dibromo-1-(p-tolyl)prop-2-ene-1-one, 3,3-dibromo-1-(m-tolyl)prop-2-ene-1-one, 3,3-dibromo-1-(4-fluorophenyl)prop-2-ene-1-one, 3,3-dibromo-1-(4-methoxyphenyl)prop-2-ene-1-one, 4-(3,3-dibromoacryloyl)benzoic acid methyl ester, 1-([1,1'-biphenyl]-4-yl)-3,3-dibromopropyl-2-ene-1-one, and 3,3-dibromo-1-(thiophene-2-yl)prop-2-ene-1-one.

6. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The non-terminal acetylene compound is selected from any one of diphenylacetylene, 2-butyne, 1,2-di-m-tolueneacetylene, 1,2-bis(4-fluorophenyl)acetylene, 1,2-di(thiophen-2-yl)acetylene, and prop-1-yn-1-ylbenzene.

7. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The catalyst is any one of dichloro(pentamethylcyclopentadienyl)ruthenium(III) polymer, tri(triphenylphosphine)carbonyldihydroruthenium(II), ruthenium trichloride, and dichloro(p-methylisopropylbenzene)ruthenium(II) dimer.

8. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The additive is any one of cupric acetate, cupric chloride, cuprous bromide, cupric trifluoroacetate and potassium persulfate.

9. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The organic solvent is any one of methanol, ethanol, acetonitrile and ethylene glycol.

10. The method for preparing γ-pyrone compounds according to claim 1, characterized in that: The method further comprises the steps of: after the reaction is completed, purifying the reaction product by thin layer chromatography, wherein the developing agent system used is petroleum ether / ethyl acetate, and the volume ratio of petroleum ether to ethyl acetate is 8-3:1.

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