Novel total synthesis method of natural products of medipterocarpin and Viss voxel

Abstract

The invention belongs to the technical field of synthetic methods of natural products, and particularly relates to a novel total synthesis method of natural products such as medipterocarpin and Vissivoxel. According to the method, resorcinol and 2, 4-dimethoxyphenylacetic acid are taken as initial raw materials, and natural products such as medipterocarpin and visivoxel are respectively obtained through a Friedel-Crafts alkylation reaction, a substitution reaction, a cyclization reaction, a demethylation / cyclization cascade reaction and a hydrogenation reduction reaction; the key steps of the method are synthesis of a pterocarpin skeleton through a demethylation / cyclization cascade reaction one-pot method of isoflavone and palladium-carbon hydrogenation reduction reaction of pterocarpin. The method is novel and reasonable in design thought, simple and easily available in raw materials, simple and efficient in route and high in reaction yield, and has very high application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthesis methods of natural products, and in particular relates to a new method for the total synthesis of the natural products meditartin and visvatin. Background Art

[0002] Isoflavones are a class of 3-phenylchromone compounds found in leguminous plants that play a role in plant defense against pathogens. Isoflavones and their derivatives are a series of natural products isolated from commercial crops. Due to their structural diversity, they possess a wide range of pharmacological activities and significant therapeutic effects. Medipterocarpin, with its core skeleton structure being pterodactyl, and vesicin, with its core skeleton being isoflavone, are two of the most widely found isoflavone compounds in nature.

[0003] Medipterocarpin, found in over thirty plants and typically isolated from the leaves and roots of Millettia repens, exhibits potent antimicrobial activity. In recent years, mediperocarpin has also been used as an intermediate in the synthesis of other isoflavones. Vesculin, extracted from leguminous plants such as Dalbergia coccinea, exhibits antioxidant and anti-Helicobacter pylori activity. Structurally, isoflavones consist of a 15-carbon tetracyclic core consisting of two benzene rings connected by a pyran ring. Isoflavone derivatives with similar core skeletons, such as mediperocarpin and vesculin, can be synthesized and transformed via a single intermediate.

[0004] In view of the excellent medicinal value of medipterostilbene and visvastatin, and the fact that there are few studies on the total synthesis of these two compounds, the synthetic strategy can be optimized. In this paper, a new total synthetic route of medipterostilbene and visvastatin was designed, and the total synthesis of the natural products medipterostilbene and visvastatin was successfully achieved. Summary of the Invention

[0005] The present invention aims to provide a novel method for the total synthesis of the natural products medipterocarpin and visvacin, wherein resorcinol and 2,4-dimethoxyphenylacetic acid are used as starting materials, and the natural products medipterocarpin and visvacin are respectively obtained through Friedel-Crafts alkylation reaction, substitution reaction, cyclization reaction, demethylation / cyclization tandem reaction and hydrogenation reduction reaction. The key steps of the present invention are the one-pot synthesis of the visvacin skeleton through the tandem demethylation / cyclization reaction of isoflavones and the palladium-carbon hydrogenation reduction reaction of visvacin. The present invention is novel and reasonable in design, has simple and readily available raw materials, a concise and efficient route, a high reaction yield, and has strong application value.

[0006] The technical solutions of the present invention are as follows:

[0007] The technical solution of the present invention is to provide a new method for the total synthesis of the natural products mediparatin and visvatin. The reaction process of the new total synthesis method is as follows:

[0008]

[0009] The reaction steps include:

[0010] Step 1: Compound 1 and compound 2 are used as starting materials, and undergo Friedel-Crafts alkylation reaction under boron trifluoride etherate to obtain substituted diphenyl acetophenone, intermediate 3; wherein compound 1 is resorcinol and compound 2 is 2,4-dimethoxyphenylacetic acid;

[0011] Step 2: The para-hydroxyl group of intermediate 3 undergoes substitution reaction with chloromethyl ether to obtain hydroxyl-protected intermediate 4;

[0012] Step 3: Intermediate 4 reacts with formaldehyde in refluxing methanol to obtain isoflavanone, intermediate 5;

[0013] Step 4: Deprotection of the hydroxyl group of intermediate 5 under hydrochloric acid conditions yields intermediate 6;

[0014] Step 5: Intermediate 6 undergoes a demethylation / cyclization tandem reaction under boron tribromide conditions to obtain intermediate 7;

[0015] Step 6: Add acetic acid to tetrahydrofuran and carry out hydrogenation reduction reaction under the catalysis of palladium on carbon to obtain the natural product meditartin 8;

[0016] Step 7: Intermediate 7 is subjected to hydrogenation reduction reaction in ethanol under the catalysis of palladium on carbon to obtain the natural product visconazole 9.

[0017] As a further option of this method, the structural formulas of the intermediates 3 to 7, the natural product mediparatin 8, and the natural product visvatin 9 are shown in the following formulas 3 to 9, respectively:

[0018]

[0019] As a further option of this method, in the preparation process of the intermediate 3, compound 1 and compound 2 are subjected to Friedel-Crafts alkylation reaction under boron trifluoride ether conditions, cooled to room temperature, diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, the solvent is removed by vortexing, and separated by elution through silica gel column chromatography to obtain intermediate 3;

[0020] The molar ratio of compound 1 to compound 2 is 1:1 to 1:2, the reaction temperature is 90 to 100 ° C, the amount of boron trifluoride ether is 2 to 3 times the total molar amount of the raw materials, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio is V 石油醚 :V 乙酸乙酯 =10:1~4:1.

[0021] As a further option of this method, in the preparation process of the intermediate 4, the intermediate is dissolved in acetone, potassium carbonate and chloromethyl ether are added and reacted, and the intermediate 4 is separated by filtration, concentration, and elution by silica gel column chromatography;

[0022] The molar ratio of the intermediate 3 to chloromethyl ether is 1:0.5 to 1:1, the reaction temperature is room temperature, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:1.

[0023] As a further option of this method, in the preparation process of the intermediate 5, the intermediate 4 is dissolved in methanol, diethylamine and formaldehyde aqueous solution are added, heated to reflux for reaction, the solvent is removed by vortexing, and the intermediate 5 is separated by elution through silica gel column chromatography;

[0024] The molar ratio of the intermediate 4 to formaldehyde is 1:1 to 1:2, the amount of diethylamine used is 2 to 3 times the molar amount of the intermediate 4, the reaction temperature is reflux temperature, the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:1.

[0025] As a further option of this method, in the preparation process of the intermediate 6, the intermediate 5 is dissolved in methanol, concentrated hydrochloric acid is added, and the reaction is carried out, and the intermediate 6 is obtained by filtration, concentration, and elution and separation by silica gel column chromatography;

[0026] The volume ratio of the intermediate 5 to concentrated hydrochloric acid is 1:1 to 1:2, the reaction temperature is room temperature, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =1:1~1:2.

[0027] As a further option of this method, in the preparation process of the intermediate 7, the intermediate 6 is dissolved in ethyl acetate under nitrogen protection and cooled, boron tribromide is added to react, cooled again, methanol is added to dilute, the solvent is removed by vortexing, and the intermediate 7 is separated by column chromatography;

[0028] The amount of boron bromide used is 3 to 4 times the amount of 6 moles of the intermediate, the cooling temperature is below -70 to -78 ° C, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio is V 石油醚 :V 乙酸乙酯 =10:1~5:1.

[0029] As a further option of this method, in the preparation process of the medipterostilbene 8, the intermediate 7 and palladium carbon are added to tetrahydrofuran, acetic acid is added dropwise, hydrogen is introduced to replace the air, and the medipterostilbene 8 is obtained by filtration, concentration, and column chromatography elution separation;

[0030] The mass ratio of intermediate 7 to palladium carbon is 1:0.05 to 1:0.2, the reaction pressure is normal pressure, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:1.

[0031] As a further option of this method, in the preparation process of visvosol 9, intermediate 7 and palladium carbon are added to tetrahydrofuran, hydrogen is introduced to replace the air, and visvosol 9 is separated by filtration, concentration, and column chromatography.

[0032] The mass ratio of intermediate 7 to palladium carbon is 1:0.05 to 1:0.2, the reaction pressure is normal pressure, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:1.

[0033] The beneficial effects brought about by the technical solutions provided in the embodiments of the present application include at least the following:

[0034] Beneficial effects:

[0035] This method uses low-cost, readily available commercial reagents as starting materials, eliminating the need for complex pretreatment. These reagents are widely available and inexpensive, significantly reducing synthesis costs and aligning with the principles of green chemistry. The entire synthetic pathway requires only six steps, and through innovative design of key steps, the tedious isolation and purification of intermediates is reduced, shortening the synthesis cycle and improving overall efficiency. The pterostilbene intermediate is efficiently converted to medi-pterostilbene and vesin under the same palladium-carbon hydrogenation system and different solvent conditions, demonstrating the flexibility and atom economy of the route. Most reactions in this synthetic method are carried out at room temperature or under reflux conditions, eliminating the need for extreme temperatures or high pressure environments, reducing reliance on specialized equipment. Key steps such as palladium-carbon hydrogenation reaction are carried out under normal pressure, avoiding the safety risks of high-pressure operation and being suitable for industrial scale-up production; the intermediates and target products are separated by silica gel column chromatography, and the elution system uses a mixed solvent of petroleum ether and ethyl acetate with a clear ratio range and a high degree of operation standardization; the yields of mediparatin and visvatin are 54% and 87%, respectively, and the structure of the purified products is verified by NMR spectrum; this method realizes the diversified synthesis of mediparatin and visvatin, providing a sustainable production path for two isoflavone compounds with important biopharmaceutical activity, which can meet the demand for natural products in the fields of pharmaceutical research and development, functional foods, etc., and at the same time provides a general strategy for the synthesis of other similar skeleton isoflavone derivatives, which has broad technical reference significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 、 2 This is the NMR spectrum of Medipterocarpin;

[0037] Figure 3 、 4 This is the Weiss voxel NMR spectrum. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0039] Preparation of intermediate 3:

[0040] 4.8 g, 24.5 mmol of m-diphenol and 3.2 g, 29.4 mmol of 2,4-dimethoxyphenylacetic acid were placed in 8 mL, 63.7 mmol of boron trifluoride etherate, heated to 100°C for 4.5 hours, cooled to room temperature, diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed by rotation. The concentrate was purified by silica gel column chromatography with petroleum ether / ethyl acetate = 5:1 to obtain intermediate 3 (white solid, 5.2 g, 74%). 1 HNMR (400MHz, CDCl3) δ12.69(s,1H),7.82(d,J=8.6Hz,1H),7.08(d,J=8.8Hz,1H) ,6.47(d,J=7.2Hz,2H),6.39-6.34(m,2H),4.15(s,2H),3.80(s,3H),3.78(s,3H).

[0041] Preparation of intermediate 4:

[0042] Intermediate 3, 5.2 g, was dissolved in 50 mL of acetone, and potassium carbonate 2.7 g, 19.8 mmol, and chloromethyl ether 1.6 mL, 18.9 mmol were added. The mixture was stirred at room temperature, filtered, and concentrated. The concentrate was purified by silica gel column chromatography using petroleum ether / ethyl acetate = 8:1 to obtain intermediate 4 (white solid, 2.4 g, 54%). 1 H NMR (400MHz, CDCl3) δ12.62(s,1H),7.84(d,J=8.9Hz,1H),7.08(d,J=8.1Hz,1H),6.59(d,J=2.5Hz,1H),6.54(dd,J=8.9,2.4 Hz,1H),6.50-6.45(m,2H),5.25(s,2H),4.16(s,2H),3.80(s,3H),3.78(s,3H),3.72(q,J=7.1Hz,2H),1.22(t,J=7.1Hz,3H).

[0043] Preparation of intermediate 5;

[0044] Intermediate 4 (2.0 g) was dissolved in 37 mL of methanol, and 0.75 mL of diethylamine (6.7 mmol) and 0.6 mL of a 37% aqueous formaldehyde solution were added. The mixture was heated under reflux for 4 hours, and the solvent was removed by vortexing. The concentrate was purified by silica gel column chromatography using petroleum ether / ethyl acetate (8:1) to obtain intermediate 5 (white solid, 1.7 g, 78%). 1H NMR (400MHz, DMSO-d6) δ7.76(d,J=8.8Hz,1H),7.01(d,J=8.4Hz,1H),6.74(dd,J=8.8 ,2.3Hz,1H),6.64(d,J=2.3Hz,1H),6.59(d,J=2.4Hz,1H),6.49(dd,J=8.4,2.4Hz,1H ),5.32(s,2H),4.58(t,J=11.3Hz,1H),4.45(dd,J=10.9,5.5Hz,1H),4.21(dd,J=11. 7,5.4Hz,1H),3.75(s,3H),3.71(s,3H),3.66(q,J=7.1Hz,2H),1.13(t,J=7.1Hz,3H).

[0045] Preparation of intermediate 6;

[0046] Intermediate 5 (1.4 g) was dissolved in 15 mL of methanol, and concentrated hydrochloric acid (0.65 mL, 7.8 mmol) was added. The mixture was stirred at room temperature for 12 hours, filtered, and concentrated. The concentrate was purified by silica gel column chromatography using petroleum ether / ethyl acetate = 1:1 to obtain intermediate 6 (white solid, 1.06 g, 91%). 1 H NMR (400MHz, DMSO-d6) δ10.59(s,1H),7.68(d,J=8.7Hz,1H),6.99(d,J=8.4Hz,1H),6.58(d,J=2.4Hz,1H),6.52(dd,J=8.7,2.2Hz,1H),6.48(dd,J=8 .4,2.4Hz,1H),6.34(d,J=2.2Hz,1H),4.52(t,J=11.2Hz,1H),4.41(dd,J= 10.9,5.4Hz,1H),4.15(dd,J=11.4,5.3Hz,1H),3.75(s,3H),3.71(s,3H).

[0047] Preparation of intermediate 7;

[0048] Intermediate 6, 0.5 g, 1.66 mmol, was dissolved in 3 mL of ethyl acetate under nitrogen protection, cooled to -78°C, and boron tribromide (0.5 mL, 5.15 mmol) was added. The mixture was reacted at room temperature for 12 hours, cooled to -78°C again, diluted with methanol, and the solvent was removed by vortexing. The concentrate was purified by silica gel column chromatography with petroleum ether / ethyl acetate = 5:1 to obtain intermediate 7 (white solid, 0.26 g, 55%). 1H NMR (400MHz, DMSO-d6) δ9.81(s,1H),7.38(d,J=8.5Hz,1H),7.25(d,J=8.2Hz,2H),6.88(dd,J= 8.6, 2.2Hz, 1H), 6.44 (dd, J=8.3, 2.3Hz, 1H), 6.38 (d, J=2.3Hz, 1H), 5.53 (s, 2H), 3.80 (s, 3H).

[0049] Synthesis of Medipterocarpin 8:

[0050] Intermediate 7, 54 mg, 0.2 mmol and 10 mol% palladium on carbon were added to 4 mL of tetrahydrofuran, 0.1 mL of acetic acid was added dropwise, and hydrogen was introduced into the system to replace the air. The reaction was carried out for 2 hours, filtered, and concentrated. The concentrate was purified by silica gel column chromatography with petroleum ether / ethyl acetate = 10:1 to obtain meditartin 8 (white solid, 29 mg, 54%). 1 H NMR (400MHz, DMSO-d6) δ9.64 (s, 1H), 7.24 (dd, J = 13.5, 8.3Hz, 2H), 6.51-6.39 (m, 3H), 6.2 6(d,J=2.4Hz,1H),5.58-5.48(m,1H),4.29-4.18(m,1H),3.69(s,3H),3.64-3.54(m,2H).

[0051] Synthesis of Vesvoxel 9:

[0052] Intermediate 7, 54 mg, 0.2 mmol and 10 mol% of palladium on carbon were added to 4 mL of tetrahydrofuran. Hydrogen was introduced into the system to replace the air. The reaction was carried out for 1 hour, filtered and concentrated. The concentrate was purified by silica gel column chromatography with petroleum ether / ethyl acetate = 10:1 to obtain visvosol 9 (white solid, 47 mg, 87%). 1 H NMR (400MHz, DMSO-d6) δ9.61(s,1H),9.18(s,1H),6.98(d,J=8.5Hz,1H),6.86(d,J= 8.2Hz,1H),6.43(d,J=2.5Hz,1H),6.34(dd,J=8.5,2.5Hz,1H),6.28(dd,J=8.2,2.4 Hz,1H),6.18(d,J=2.3Hz,1H),4.17-4.09(m,1H),3.90(t,J=10.1Hz,1H),3.66(s,3 H), 3.37-3.25 (m, 1H), 2.87 (dd, J=15.5, 10.9Hz, 1H), 2.71 (dd, J=15.6, 4.0Hz, 1H).

[0053] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0054] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be applied in the widest sense consistent with the principles and novel features of the present invention.

[0055] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A new method for the total synthesis of natural products medipterostilbene and viscera, characterized in that: The novel total synthesis process is as follows: The reaction steps include: Step 1: Compound 1 and compound 2 are used as starting materials, and undergo Friedel-Crafts alkylation reaction under boron trifluoride etherate to obtain substituted diphenyl acetophenone, intermediate 3; wherein compound 1 is resorcinol and compound 2 is 2,4-dimethoxyphenylacetic acid; Step 2: The para-hydroxyl group of intermediate 3 undergoes substitution reaction with chloromethyl ether to obtain hydroxyl-protected intermediate 4; Step 3: Intermediate 4 reacts with formaldehyde in refluxing methanol to obtain isoflavanone, intermediate 5; Step 4: Deprotection of the hydroxyl group of intermediate 5 under hydrochloric acid conditions yields intermediate 6; Step 5: Intermediate 6 undergoes a demethylation / cyclization tandem reaction under boron tribromide conditions to obtain intermediate 7; Step 6: Add acetic acid to tetrahydrofuran and carry out hydrogenation reduction reaction under the catalysis of palladium on carbon to obtain the natural product meditartin 8; Step 7: Intermediate 7 is subjected to hydrogenation reduction reaction in ethanol under the catalysis of palladium on carbon to obtain the natural product visconazole 9.

2. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: The structural formulas of the intermediates 3, 4, 5, 6, 7, the natural product mediparatin 8, and the natural product viscerin 9 are shown in the following formulas 3 to 9, respectively:

3. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: In the preparation process of the intermediate 3, compound 1 and compound 2 are subjected to Friedel-Crafts alkylation reaction under boron trifluoride ether conditions, cooled to room temperature, diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, the solvent is removed by rotation, and separated by elution through silica gel column chromatography to obtain intermediate 3; The molar ratio of compound 1 to compound 2 is 1:1 to 1:2, the reaction temperature is 90 to 100 ° C, the amount of boron trifluoride ether is 2 to 3 times the total molar amount of the raw materials, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio is V 石油醚 :V 乙酸乙酯 =10:1~4:

1.

4. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: In the preparation process of the intermediate 4, the intermediate is dissolved in acetone, potassium carbonate and chloromethyl ether are added and reacted, and the intermediate 4 is separated by filtration, concentration, and elution by silica gel column chromatography; The molar ratio of the intermediate 3 to chloromethyl ether is 1:0.5 to 1:1, the reaction temperature is room temperature, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:

1.

5. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: During the preparation of the intermediate 5, the intermediate 4 was dissolved in methanol, diethylamine and formaldehyde solution were added, the reaction was heated under reflux, the solvent was removed by vortexing, and the intermediate 5 was isolated by elution through silica gel column chromatography; The molar ratio of the intermediate 4 to formaldehyde is 1:1 to 1:2, the amount of diethylamine used is 2 to 3 times the molar amount of the intermediate 4, the reaction temperature is reflux temperature, the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:

1.

6. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: During the preparation of the intermediate 6, the intermediate 5 is dissolved in methanol, concentrated hydrochloric acid is added and reacted, and the intermediate 6 is obtained by filtration, concentration, and elution and separation by silica gel column chromatography; The volume ratio of the intermediate 5 to concentrated hydrochloric acid is 1:1 to 1:2, the reaction temperature is room temperature, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =1:1~1:

2.

7. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: During the preparation of the intermediate 7, the intermediate 6 was dissolved in ethyl acetate under nitrogen protection and cooled, boron tribromide was added to react, cooled again, methanol was added to dilute, the solvent was removed by vortexing, and the intermediate 7 was isolated by column chromatography; The amount of boron bromide used is 3 to 4 times the amount of 6 moles of the intermediate, the cooling temperature is below -70 to -78 ° C, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio is V 石油醚 :V 乙酸乙酯 =10:1~5:

1.

8. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: In the preparation process of the described medipterostilbene 8, the intermediate 7 and palladium carbon are added to tetrahydrofuran, acetic acid is added dropwise, hydrogen is introduced to replace the air, and the medipterostilbene 8 is obtained by filtration, concentration, and column chromatography. The mass ratio of intermediate 7 to palladium carbon is 1:0.05 to 1:0.2, the reaction pressure is normal pressure, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:

1.

9. A novel method for the total synthesis of the natural products medipterocarpin and visvatin as claimed in claim 1 or 2, characterized in that: During the preparation of visvosol 9, intermediate 7 and palladium carbon are added to tetrahydrofuran, hydrogen is introduced to replace the air, and visvosol 9 is separated by filtration, concentration, and column chromatography. The mass ratio of intermediate 7 to palladium carbon is 1:0.05 to 1:0.2, the reaction pressure is normal pressure, and the eluent used for silica gel column chromatography is a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio V 石油醚 :V 乙酸乙酯 =10:1~5:1.

Images