CN107973830B - Total synthesis method of neooxytocin - Google Patents

Abstract

The invention belongs to the technical field of medicinal chemistry and organic synthesis, and aims to provide a method for chemically synthesizing neo-Othomycin, which specifically includes: using D-galactose and the like as raw materials, firstly obtaining compound 14 through 8-step reactions, and then reacting with urine Pyrimidine is condensed to obtain compound 15, and then 4-step reaction is performed to obtain compound 19, which is then condensed with compound 6 to obtain compound 20. Finally, the ester protecting group is removed in turn, and then the Cbz protecting group is removed to obtain the natural product neoorthomycin. The present invention is the first method for synthesizing natural product neoorthomycin. The invention has the advantages of high product purity, low cost, simple operation and the like.

Description

A kind of total synthesis method of neoorthomycin

technical field

The invention belongs to the technical field of medicinal chemistry and organic synthesis, and in particular relates to a chemical synthesis method of neo-Othomycin.

Background technique

As a new type of pesticide, biopesticides have developed rapidly in recent decades due to their green environmental protection, safety and high efficiency (Trends in Biotechnology 2012, 30, 250-258; Phil. Trans.R.Soc.B2011,366,1987- 1998; Biosystems Engineering 2003, 84, 119-125 et al). Among them, nucleoside antibiotics have attracted great interest in chemical synthesis workers because of their wide range of biological activities (J. Antibiot. 1988, 41, 1711-1739; Pharm. Therap. 1991, 52, 269-286; Nat. Prod. Rep. 2010, 27, 279-304; Trends in Microbiology 2015, 23, 110-119, etc.). Many literatures have reported that some nucleoside antibiotics have good application prospects in crop protection (Chem. Rev. 1992, 92, 1745-1768; Chem. Rev. 1995, 95, 1859-1876; .Sci.2007, 63, 524-554, etc.).

Xinaomycin is a polypeptide nucleoside agricultural antibiotic, which is isolated from the fermentation broth of Streptomyces knowlesii xinao-4 (CN200910060121). As a broad-spectrum nucleoside agricultural antibiotic, neoorthomycin has antibacterial, antifungal and antiviral activities. The field efficacy test showed that 4% neo-octomycin water has a good effect on the prevention and control of tobacco mosaic virus disease, and it is significantly higher than the commercial control agent 20% morphine·copper acetate wettable powder (Mod. Agrochem .2011, 10, 50-52); has a good control effect on tomato mosaic virus disease, and is safe for tomato growth (J. Henan Agric. Sci. 2013, 42, 86-88); Bacterial diseases such as bacterial wilt, bacterial wilt and soft rot also have control effects. In addition, neoorthomycin showed strong inhibitory activity against Sclerotinia sclerotiorum and Rhizoctonia solani, and its bacteriostatic effect was comparable to that of polyantimycin (Agrochemicals 2013, 52, 293-294).

However, the yield of neoorthomycin obtained by microbial fermentation is low. In order to improve the yield of neo-octomycin, some studies on the biosynthetic gene cluster of neo-octomycin have been carried out. Although some progress has been made in the study of the xinao-4 gene manipulation system of Streptomyces knowlesii, the problem of the low yield of biosynthetic neoorthomycin remains unsolved (Int.J.Mol.Sci.2014, 15, 12217 -12230). In addition, due to the high polarity of neoorthomycin, the fermentation broth contains a large amount of amino acids and carbohydrates, the composition is complex, and there are many homologs, which lead to certain difficulties in separation and purification. Therefore, it is very meaningful to obtain a large amount of high-purity neo-octomycin.

Total chemical synthesis is an important technical idea to obtain a large number of high-purity natural products. However, there is no report on the total synthesis of neoorthomycin.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for the total chemical synthesis of neo-Othomycin, that is, using D-galactose and the like as raw materials, through a series of reactions, the total chemical synthesis of neo-Othomycin is realized.

In order to achieve the above purpose of the invention, the present invention has synthesized a new chemical substance: compound 18, and further reacted with compound 18 to synthesize neoorthomycin.

Compound 18, named: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucuronide methyl uridine, the chemical structure is:

Correspondingly, the preparation method of compound 18 specifically includes the following steps:

1), add 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucouridine, referred to as: compound 16, and add CH together with TEMPO ₃ CN, then add iodobenzene acetate, and the reaction is complete, then add anhydrous EtOH to quench the reaction, concentrate to obtain a solid crude product, named: compound 17;

2), the compound 17 was dissolved in anhydrous CH ₃ OH, added H ₂ SO ₄ , the reaction was complete, then NaHCO ₃ was added to quench the reaction, and concentrated; the reaction solution was extracted with ethyl acetate, then dried, filtered, and decompressed. Concentration gave compound 18.

Preferably, in the preparation method of compound 18, the synthesis method of compound 14 is:

1), the backflow reaction of compound 14 and uracil under TMSOTf/BSA/acetonitrile conditions obtains compound 15, and compound 15 is hydrolyzed in Et ₃ N/CH ₃ OH to obtain compound 16; the names of the compounds 14 and 15 are respectively: Compound 14: 1,6-Di-O-acetyl-2,3-di-O-benzoyl-4-azido-4-deoxy-α-D-glucose; Compound 15: 2',3 '-Di-O-benzoyl-4'-azido-6'-O-acetyl-4'-deoxy-α-D-glucouridine;

2), the synthetic method of described compound 14 is:

Compound 13 was reacted under the condition of H ₂ SO ₄ /AcOH/Ac ₂ O to obtain compound 14; the name of compound 13 was: 2,3-di-O-benzoyl-4-azido-6-O - tert-butyldimethylsilyl-4-deoxy-α-D-glucoside methyloside;

3) The synthesis method of the compound 13 is as follows: the compound 11 is hydrolyzed in CH ₃ ONa/CH ₃ OH, and then imidazole and TBSCl are added to the DMF to react to obtain the compound 12, and the compound 12 is reacted with BzCl in the pyridine to obtain the compound 13; The names of the compounds 11 and 12 are respectively: compound 11: 4-azido-2,3,6-tri-O-benzoyl-4-deoxy-α-D-glucoside, compound 12: 4-Azido-6-O-tert-butyldimethylsilyl-4-deoxy-α-D-glucoside methyloside.

Further, compound 19 synthesized by compound 18 is named: 2',3'-di-O-benzoyl-4'-amino-4'-deoxy-α-D-glucuronate methyl uridine , the chemical structure is:

Correspondingly, the preparation method of the compound 19 is as follows: the compound 18 is reacted with SnCl ₂ ·H ₂ O, p-methylthiophenol, CHCl ₃ and Et ₃ N, and the compound 19 is obtained by isolation.

Further, compound 20 synthesized by compound 19 is named: (R)-2',3'-di-O-benzoyl-4'-(2"-(2"'-(N-methyl, N-Cbz) amino) acetamido-3 "-hydroxyl) propionamido-4'-deoxy-α-D-glucuronide methyl uridine, the chemical structural formula is:

Correspondingly, the preparation method of the compound 20 is as follows: using the compound 19, (R)-2-[2'-(N-methyl, N-Cbz)amino]acetamido-3-hydroxypropionic acid as The raw materials were fully reacted with HATU as a condensing agent and 2,6-lutidine as a base, and after extraction, washing, drying, filtration and concentration, compound 20 was isolated and obtained.

Further, compound 21 synthesized by compound 20 is named: (R)-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido-3"-hydroxyl) Propionamido-4'-deoxy-α-D-glucuronide uridine, the chemical structure is:

Correspondingly, the preparation method of the compound 21 is as follows: the compound 20 is hydrolyzed in LiOH aqueous methanol solution at 0°C, concentrated and prepared by HPLC to obtain the compound 21.

Further, the total synthesis method of using the compound 21 to synthesize neoorthomycin is as follows: the compound 21 and Pd/C with a content of 10% are added to EtOH and water, the reaction is completed at room temperature under the condition of hydrogen, and the mixture is filtered and purified. Concentration yields neo-Othomycin.

Correspondingly, the intermediates of the total synthesis of neo-Othomycin obtained and utilized in the present invention are novel and have independent use and protection value, and patent protection is requested.

Beneficial effects of the present invention:

1, the present invention is the method for synthesizing natural product neoorthomycin for the first time, and truly realizes its artificial total synthesis;

2. The present invention uses cheap and easy-to-obtain D-galactose and the like as starting materials, and has the characteristics of low cost, simple operation and extremely high product purity;

3. The synthetic route of the present invention can simultaneously carry out various modifications at multiple positions of the chemical structure of neo-Othomycin, which lays a foundation for the synthesis of neo-Othomycin structural analogs and the development of new high-efficiency and low-toxic biological pesticides.

Description of drawings

Fig. 1 is the total synthesis route map of neo-Othomycin;

Figure 2 shows the hydrogen NMR spectrum of compound 18: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucuronide methyl uridine ;

Figure 3 is the carbon NMR spectrum of compound 18: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucuronide methyl uridine ;

Fig. 4 is compound 19: 2',3'-di-O-benzoyl-4'-amino-4'-deoxy-α-D-glucuronic acid methyl uridine hydrogen NMR spectrum;

Figure 5 is the carbon nuclear magnetic resonance spectrum of compound 19: 2',3'-di-O-benzoyl-4'-amino-4'-deoxy-α-D-glucuronate methyl uridine;

Figure 6 is compound 20: (R)-2',3'-di-O-benzoyl-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido -3"-Hydroxy)propionamido-4'-deoxy-α-D-glucuronide methyl uridine 1H NMR spectrum;

Figure 7 is compound 20: (R)-2',3'-di-O-benzoyl-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido -3"-Hydroxy)propionamido-4'-deoxy-α-D-glucuronide methyl uridine carbon NMR spectrum;

Figure 8 is compound 21: (R)-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido-3"-hydroxy)propionamido-4'-de 1H NMR spectrum of oxygen-α-D-glucuronide uridine;

Figure 9 is compound 21: (R)-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido-3"-hydroxy)propionamido-4'-de Carbon NMR spectrum of oxygen-α-D-glucuronide uridine;

Figure 10 is compound 22: (R)-4'-(2"-(2"'-(N-methyl)amino)acetamido-3"-hydroxy)propionamido-4'-deoxy-α- 1H NMR spectrum of uridine D-glucuronide (neoorthomycin);

Figure 11 is compound 22: (R)-4'-(2"-(2"'-(N-methyl)amino)acetamido-3"-hydroxy)propionamido-4'-deoxy-α- C NMR spectrum of uridine D-glucuronide (neoorthomycin);

Figure 12 is the natural product neo-octomycin: (R)-4'-(2"-(2"'-(N-methyl)amino)acetamido-3"-hydroxy)propionamido-4'-de 1H NMR spectrum of oxo-α-D-glucuronide uridine (natural product neo-Othomycin);

Figure 13 is the natural product neo-octomycin: (R)-4'-(2"-(2"'-(N-methyl)amino)acetamido-3"-hydroxy)propionamido-4'-de Carbon NMR spectrum of oxo-α-D-glucuronide uridine (a natural product neo-othomycin).

Detailed ways

Since the present invention involves a series of chemical reactions, a detailed example is provided to enable those skilled in the art to understand the technical solutions of the present invention. It should be clear to those skilled in the art that, on the basis of the present embodiment, appropriate adjustment of synthetic raw materials, process methods and parameters to achieve the same purpose are all within the protection scope of the present invention.

1. Synthesis: D-serine methyl ester hydrochloride (compound 2)

The chemical reaction equation is:

Because the present invention involves a large number of compounds and chemical reaction equations, for the sake of more convenient description and elaboration, all important intermediate products in the synthesis steps are all labeled in the full text, and the labeling method is: compound + number, as shown in this example, D -Serine methyl ester hydrochloride is abbreviated as: compound 2; and the corresponding serial number is indicated below the chemical structural formula in the chemical reaction equation. As shown in this example, it is indicated below the structural formula of D-serine methyl ester hydrochloride: 2.

Thionyl chloride (18.68 g, 157.00 mmol) was slowly added dropwise to anhydrous CH ₃ OH (30 mL) cooled in an ice-salt bath under the protection of N ₂ . After the dropwise addition, the reaction solution was warmed to room temperature and stirred for half an hour . Then, compound 1 (5.00 g, 47.58 mmol) as described in the above reaction formula was added, and the reaction was carried out at room temperature for 12 hours, and the reaction solution became clear from turbidity. The reaction solution was concentrated and dried in vacuo to obtain a white solid: compound 2 (7.10 g, 96%).

Compound 2 is an existing raw material and can also be purchased directly.

2. Synthesis: 2-(N-methyl, N-Cbz)aminoacetic acid (compound 4)

The chemical reaction equation is:

Compound 3 sarcosine (3.00 g, 33.67 mmol) was added to an aqueous solution of NaOH (3.24 g, 80.90 mmol) (100 mL), and the mixture was stirred under an ice-water bath to form a homogeneous phase. CbzCl (6.89 g, 40.39 mmol) was added dropwise. After stirring at room temperature for 16 hours, the starting material was monitored by TLC for completion. The reaction solution was washed with ethyl acetate (2 x 100 mL), the aqueous layer was washed with 1 M hydrochloric acid to pH 2, then extracted with ethyl acetate (2 x 150 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (100 mL), dried over anhydrous Na ₂ SO ₄ , filtered, and concentrated under reduced pressure to give a colorless oil N-Cbz-sarcosine: compound 4 (7.11 g, 94 %).

3. Synthesis: (R)-2-[2'-(N-methyl, N-Cbz)amino]acetamido-3-hydroxypropionic acid methyl ester (Compound 5)

The chemical reaction equation is:

Compound 4 (6.00 g, 26.88 mmol) was dissolved in dry DMF (80 mL), followed by the addition of HATU (18.33 g, 48.21 mmol) and 2,6-lutidine (10.14 g, 94.62 mmol), and the mixture was heated to room temperature under stirring for 2 hours. The above compound 2 (5.80 g, 37.30 mmol) was added, and after stirring at room temperature for 14 hours, TLC monitored the reaction of the starting materials to complete. Saturated NaCl solution (250 mL) was added, and the reaction solution was extracted with ethyl acetate (3×200 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 200 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (CH ₂ Cl ₂ /MeOH, 50:1) to give a colorless oil: compound 5 (6.45 g, 74%).

4. Synthesis: (R)-2-[2'-(N-methyl, N-Cbz)amino]acetamido-3-hydroxypropionic acid (compound 6)

The chemical reaction equation is:

Compound 5 (3.80 g, 11.72 mmol) was dissolved in CH ₃ OH (30 mL), and an aqueous solution (10 mL) of LiOH·H ₂ O (639.3 mg, 15.24 mmol) was added dropwise at 0°C. After stirring for 1 hour, TLC monitored the completion of the starting material. 1M hydrochloric acid was added dropwise to adjust the solution to pH=1. Water (100 mL) was added and extracted with ethyl acetate (2 x 150 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (100 mL), dried over anhydrous Na ₂ SO ₄ , filtered, and concentrated under reduced pressure to give a white solid: compound 6 (2.76 g, 76%).

5. Synthesis: 4-hydroxy-2,3,6-tri-O-benzoyl-α-D-galactoside (compound 9)

The chemical reaction equation is:

Acetyl chloride (7.5 mL) was added dropwise to anhydrous methanol (350 mL) cooled in an ice-water bath. After the dropwise addition, the reaction solution was warmed to room temperature and stirred for half an hour. Then, compound 7: D-galactose (25.00 g, 0.14 mol) as described in the above reaction equation was added, and the mixture was heated to reflux for 12 hours under nitrogen protection, and the reaction solution changed from turbid to clear. The reaction solution was cooled to room temperature, and solid NaHCO ₃ was added to adjust pH=8. Filter, concentrate the filtrate, and dry the solvent with an oil pump to obtain a crude product: compound 8 (34.3 g), which is directly subjected to the next reaction. Compound 8 (34.3 g) was dissolved in pyridine (300 mL) and cooled at -20°C. BzCl (68.39 g, 0.49 mol) was added dropwise, and the mixture was slowly warmed to room temperature and stirred for 18 hours. The reaction was quenched by dropwise addition of methanol (50 mL). Concentrate, add water (800 mL), and extract the reaction solution with ethyl acetate (3×500 mL). The combined ethyl acetate solution was washed with 1M hydrochloric acid to pH=2, then with saturated NaCl solution (2 x ₄₀₀ mL), dried over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 8:1) to obtain a colorless oily substance: compound 9: 4-hydroxy-2,3,6-tri-O-benzoyl-α - D-galactoside (35.90 g, 51%, two steps). ¹ H NMR (400MHz, CDCl ₃ ) δ 8.10-7.97 (m, 6H), 7.64-7.37 (m, 9H), 5.78 (dd, J=10.7, 2.9Hz, 1H), 5.72 (dd, J=10.7 ,3.5 Hz,1H),5.24(d,J＝3.4Hz,1H),4.70(dd,J＝11.4,5.8Hz,1H),4.59(dd,J＝11.4,6.9Hz,1H),4.43(d , J=1.6Hz, 1H), 4.38(t, J=6.3Hz, 1H), 3.47(s, 3H), 2.84–2.50(br, 1H); ¹³ C NMR(100MHz, CDCl ₃ )δ166.5,166.1, 165.8, 133.5, 133.3, 129.9, 129.8, 129.7, 129.6, 129.3, 128.5, 128.4, 97.5, 70.8, 68.9, 68.2, 67.7, 63.4, 55.5.

6. Synthesis: 4-azido-2,3,6-tri-O-benzoyl-4-deoxy-α-D-glucoside (compound 11)

The chemical reaction equation is:

Compound 9 (10.00 g, 19.74 mmol) and pyridine (6.25 g, 78.96 mmol) were dissolved in CH ₂ Cl ₂ (100 mL), and Tf ₂ O (5.57 g, 19.74 mmol) was added dropwise at -10°C. After 1.5 hours of reaction at -10°C, the reaction of the starting material was monitored by TLC for completion. The reaction solution was washed with 1M hydrochloric acid to pH=2, then washed with water (2×100 mL), dried over anhydrous Na ₂ SO ₄ , filtered, and concentrated under reduced pressure to obtain crude product: compound 10, which was directly carried out to the next reaction. The crude compound was dissolved in DMF (80 mL) and NaN3 ₍ 2.57 g, 39.48 mmol) was added. After 16 hours at room temperature, TLC monitored the starting material for completion. Saturated NaCl solution (300 mL) was added to the reaction solution, followed by extraction with ethyl acetate (3×200 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 200 mL) and dried _over anhydrous _Na2SO4 . Filter and concentrate under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 12:1) to obtain a colorless oil: compound 11: 4-azido-2,3,6-tri-O-benzoyl - 4-Deoxy-α-D-glucoside tetrakis (7.87 g, 75%, two steps). ¹ H NMR (600 MHz, CDCl ₃ ) δ 8.11 (d, J=7.4 Hz, 2H), 8.00 (d, J=7.4 Hz, 2H), 7.97 (d, J=7.4 Hz, 2H), 7.61 (t , J＝7.4Hz, 1H), 7.54–7.48(m, 4H), 7.38(q, J＝7.5Hz, 4H), 6.00(t, J＝9.9Hz, 1H), 5.20(dd, J＝10.0, 3.6Hz, 1H), 5.17(d, J＝3.6Hz, 1H), 4.71(dd, J＝12.1, 2.1Hz, 1H), 4.63(dd, J＝12.1, 4.7Hz, 1H), 4.09–4.03( m, 1H), 3.86 (t, J=10.1 Hz, 1H), 3.44 (s, 3H); ¹³ C NMR (100 MHz, CDCl ₃ ) δ 166.2, 160.0, 165.6, 133.5, 133.4, 130.0, 129.9, 129.8, 129.6 ,129.1,128.9,128.6,128.5,97.2,71.9,71.0,68.0,63.4,61.0,55.7.

7. Synthesis: 4-azido-6-O-tert-butyldimethylsilyl-4-deoxy-α-D-glucoside (Compound 12)

The chemical reaction equation is:

Compound 11 (20.00 g, 37.63 mmol) was dissolved in CH3OH (100 mL ₎ and _CH3ONa (0.61 g, 11.29 mmol) was added. After 15 hours at room temperature, the reaction was completed by TLC monitoring. Concentrated and evacuated to constant weight to obtain crude product. The crude product was dissolved in DMF (80 mL), imidazole (7.69 g, 11 mmol) was added, and TBSCl (8.51 g, 56.44 mmol) was added portionwise at 0 °C. After slowly warming to room temperature for 16 hours, the reaction was monitored by TLC for completion. Saturated NaCl solution (300 mL) was added to the reaction solution, followed by extraction with ethyl acetate (4×200 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 200 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 5:1-1:1) to obtain a colorless oil: compound 12 (7.90 g, 63%). ¹ H NMR(400MHz, CDCl ₃ )δ4.79(d,J=3.8Hz,1H),3.84(d,J=1.0Hz,2H),3.81(t,J=9.3Hz,1H),3.55(dd , J=9.5, 3.8Hz, 1H), 3.51–3.46 (m, 2H), 3.41 (s, 3H), 3.33–3.10 (br, 2H), 0.93 (s, 9H), 0.10 (s, 6H); ¹³ CNMR (100MHz, CDCl ₃ ) δ 99.2, 73.4, 72.5, 70.8, 62.5, 61.5, 55.3, 25.9, 18.4, -5.3, -5.4.

8. Synthesis: 2,3-di-O-benzoyl-4-azido-6-O-tert-butyldimethylsilyl-4-deoxy-α-D-glucoside (Compound 13 )

The chemical reaction equation is:

Compound 12 (7.50 g, 22.49 mmol) was dissolved in pyridine (80 mL), and BzCl (7.59 g, 53.98 mmol) was added dropwise at 0°C. After 16 hours at room temperature, the reaction was completed by TLC monitoring. The reaction was quenched by dropwise addition of methanol (10 mL). Concentrate, add water (200 mL), and extract the reaction solution with dichloromethane (3 x 200 mL). The combined dichloromethane solution was washed with 1M hydrochloric acid to pH=2, saturated NaCl solution (2 x 200 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 20:1) to obtain a colorless oil: compound 13 (11.01 g, 90%). ¹ H NMR (400MHz, CDCl ₃ ) δ 8.09-7.96 (m, 4H), 7.57-7.48 (m, 2H), 7.44-7.36 (m, 4H), 5.96 (dd, J=15.6, 5.6Hz, 1H) ,5.20–5.14(m,2H),4.01–3.90(m,3H),3.76(dd,J=10.2,1.5Hz,1H), 3.42(s,3H),1.00(s,9H),0.18(s , 3H), 0.17(s, 3H); ¹³ CNMR (100MHz, CDCl ₃ ) δ 166.0, 165.7, 133.4, 133.3, 130.0, 129.9, 129.8, 129.3, 129.1, 128.4, 97.1, 72.1, 71.1, 70.4, 62.2, 60.3 ,55.4,26.0,18.5,-5.2,-5.4.

9. Synthesis: 1,6-di-O-acetyl-2,3-di-O-benzoyl-4-azido-4-deoxy-α-D-glucose (compound 14)

The chemical reaction equation is:

Compound 13 (10.00 g, 18.46 mmol) was added to AcOH (33 mL) and Ac ₂ O (67 mL), and H ₂ SO ₄ (2.0 mL) was added dropwise at 0°C. After 2 days of reaction at 0°C, the completion of the reaction was monitored by TLC. The reaction solution was poured into ice water (400 mL) and extracted with dichloromethane (3×200 mL). The combined dichloromethane solution was washed with water (2 x 400 mL), saturated NaHCO ₃ solution to pH=8, saturated NaCl solution (2 x 300 mL), dried over anhydrous Na ₂ SO ₄ , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 3:1) to obtain a white solid: compound 14 (5.41 g, 59%). ¹ HNMR (400MHz, CDCl ₃ ) δ 8.03 (d, J=7.6Hz, 2H), 7.92 (d, J=7.5Hz, 2H), 7.60-7.49 (m, 2H), 7.46-7.36 (m, 4H) ),6.54(d,J＝3.6Hz,1H),5.96(t,J＝10.0Hz,1H),5.42(dd,J＝10.2,3.6Hz,1H),4.48–4.36(m,2H),4.05 (d, J=10.3Hz, 1H), 3.94 (t, J=10.2Hz, 1H), 2.20 (s, 6H); ¹³ CNMR (100MHz, CDCl ₃ ) δ 170.5, 168.6, 165.6, 165.4, 133.7, 133.6, 129.8, 128.7, 128.5, 89.3, 70.8, 70.4, 70.1, 62.5, 60.3, 20.8.

10. Synthesis: 2',3'-di-O-benzoyl-4'-azido-6'-O-acetyl-4'-deoxy-α-D-glucouridine (compound 15)

The chemical reaction equation is:

Uracil (1.38 g, 12.33 mmol) and BSA (7.53 g, 37.00 mmol) were added to CH ₃ CN (40 mL), and stirred at room temperature for 10 minutes, the reaction solution turned from turbid to clear. Compound 14 (4.09 g, 8.22 mmol) was added followed by TMSOTf (12.79 g, 57.55 mmol). After heating at reflux under _N2 for 16 h, the reaction was complete as monitored by TLC. Concentrate, add water (200 mL), and extract the reaction solution with ethyl acetate (3 x 200 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 200 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. _The resulting crude product was recrystallized from CH3OH to give a pale yellow solid: compound 15 (3.58 g, 79%). ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.37 (s, 1H), 7.92 (d, J=8.1 Hz, 3H), 7.77 (d, J=7.3 Hz, 2H), 7.71-7.58 (m, 2H) ), 7.55–7.42 (m, 4H), 6.33 (d, J=9.1Hz, 1H), 6.05 (t, J=9.5Hz, 1H), 5.80–5.69 (m, 2H), 4.41 (d, J= 11.8Hz, 1H), 4.34–4.28 (m, 1H), 4.26–4.13 (m, 2H), 2.11 (s, 3H).

11. Synthesis: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucouridine (Compound 16)

The chemical reaction equation is:

Compound 15 (3.14 g, 5.71 mmol) was dissolved in anhydrous CH3OH (200 mL) and _{Et3N (} 4.04 g, 40.00 mmol) was added. After 48 hours of reaction at room temperature, the reaction solution turned from turbid to clear, and TLC monitored the reaction to complete. The reaction solution was concentrated at 40°C to obtain a solid crude product. Washed with ether to give pale yellow solid: compound 16 (2.47 g, 85%).

12. Synthesis: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucuronide methyl uridine (compound 18)

The chemical reaction equation is:

Compound 16 (1.20 g, 2.37 mmol), TEMPO (73.9 mg, 0.47 mmol) were added to _CH3CN (15 mL) and water (12 mL). Iodobenzene acetate (1.90 g, 5.91 mmol) was added in portions, and after stirring at room temperature for 6 hours, TLC monitored the reaction to complete. The reaction was quenched by the addition of anhydrous EtOH (5 mL) and concentrated. The obtained crude product: compound 17, directly proceed to the next reaction. The above crude product was dissolved in anhydrous CH3OH ( ₂₀ mL ₎ and _H2SO4 (0.4 mL) was added. After heating at reflux for 4 hours, TLC monitored the reaction for completion. The reaction was quenched by the addition of _NaHCO3 and concentrated. Water (40 mL) was added, and the reaction solution was extracted with ethyl acetate (3×40 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 50 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (petroleum ether/ethyl acetate, 1:1) to obtain a white solid: compound 18 (558.1 mg, 44%, two steps). ¹ H NMR (400 MHz, CDCl ₃ ) δ 8.27 (s, 1H), 7.97 (d, J=7.2 Hz, 2H), 7.87 (d, J=7.2 Hz, 2H), 7.60-7.46 (m, 3H) , 7.45–7.34 (m, 4H), 6.15 (d, J=9.5Hz, 1H), 5.90–5.74 (m, 2H), 5.57 (t, J= 9.5Hz, 1H), 4.30–4.13 (m, 2H) _The ^_ _{_} , 127.62, 103.88, 80.71, 77.26, 75.84, 72.80, 69.50, 61.40, 53.51. ESI-HRMS: m/zcalcd for C ₂₅ H ₂₂ N ₅ O ₉ [M+H] ⁺ :536.1412; found: 536.1419.

13. Synthesis: 2',3'-di-O-benzoyl-4'-amino-4'-deoxy-α-D-glucuronate methyl uridine (compound 19)

The chemical reaction equation is:

SnCl ₂ ·H ₂ O (295.0 mg, 1.31 mmol), p-methylthiophenol (324.9 mg, 2.62 mmol) were added to CHCl ₃ (5 mL), and Et ₃ N (396.3 mg, 3.92 mmol) was added dropwise at room temperature ). After stirring for 5 minutes, compound 18 (350.0 mg, 0.65 mmol) was added. After 2 hours at room temperature, TLC monitored the completion of the reaction. Silica gel was added to the mixture, and the mixture was separated by silica gel column chromatography (CH ₂ Cl ₂ /CH ₃ OH, 40:1) to obtain a white solid: compound 19 (288.1 mg, 86%). ¹ H NMR (400 MHz, DMSO-d ₆ ) δ 11.39 (s, 1H), 7.99 (d, J=8.1 Hz, 1H), 7.90 (d, J=7.3 Hz, 2H), 7.75 (d, J= 7.3Hz, 2H), 7.61 (t, J=7.4Hz, 2H), 7.46 (q, J=8.0Hz, 4H), 6.17 (d, J=8.3Hz, 1H), 5.78–5.62 (m, 3H) , 4.50 (d, J=10.1Hz, 1H), 3.73 (s, 3H), 1.93–1.61 (br, 2H, NH ₂ ). ¹³ CNMR (101MHz, DMSO) δ 168.71, 165.95, 165.03, 163.09, 150.81, 141.46 ,134.37,133.94,129.74,129.55, 129.31,129.10,128.70,103.14,78.56,76.12,71.36,53.70,52.75,29.48. ESI-HRMS:m/zcalcdforC ₂₅ H ₂₃ N ₃ O ₉ :M ⁺ H] 509.1434; found: 510.1514.

14. Synthesis: (R)-2',3'-di-O-benzoyl-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido-3 "-Hydroxy)propionamido-4'-deoxy-α-D-glucuronide methyl uridine (Compound 20)

The chemical reaction equation is:

The above compound 6 (200 mg, 0.65 mmol) was dissolved in dry DMF (5 mL), followed by the addition of HATU (490.0 mg, 1.29 mmol) and 2,6-lutidine (172.5 mg, 1.61 mmol) in sequence, and the mixture was heated to room temperature. under stirring for 2 hours. Compound 19 (164.1 mg, 0.32 mmol) was added, and after stirring at room temperature for 14 hours, the reaction of the starting materials was monitored by TLC for completeness. Saturated NaCl solution (30 mL) was added, and the reaction solution was extracted with ethyl acetate (3×30 mL). The combined ethyl acetate solution was washed with saturated NaCl solution (2 x 30 mL), dried _over anhydrous _Na2SO4 , filtered and concentrated under reduced pressure. The obtained concentrate was separated by silica gel column chromatography (CH ₂ Cl ₂ /CH ₃ OH, 50:1) to obtain a white solid: compound 20 (178.0 mg, 69%). ¹ HNMR (400MHz, DMSO-d ₆ ) δ 11.40 (s, 1H), 8.24 (t, J=7.4Hz, 1H), 8.15 (d, J=8.1Hz, 1H), 8.03 (d, J=7.9 Hz, 1H), 7.77(d, J=7.3Hz, 4H), 7.66–7.57 (m, 2H), 7.50–7.41 (m, 4H), 7.39–7.26 (m, 5H), 6.21 (d, J= 8.5Hz, 1H), 5.89–5.77 (m, 2H), 5.74 (d, J=8.1Hz, 1H), 5.08 (s, 1H), 5.02 (dd, J=21.3, 8.4Hz, 1H), 4.73– 4.61(m, 3H), 4.33-4.22(m, 1H), 3.99-3.80(m, 2H), 3.57(d, J=16.9Hz, 3H, O-CH ₃ ), 3.31-3.15(m, 2H) , 2.84 (d, J=16.4Hz, 3H, N-CH ₃ ). ¹³ CNMR (150MHz, D ₂ O) δ 170.72, 168.49, 167.54, 165.75, 164.93, 163.10, 156.42, 156.11, 150.81, 141.64, 137.421, 134. ,129.65,129.62,129.48,129.33,129.05, 128.87,128.66,128.26,127.85,127.57,103.16,75.24,73.27,71.26,66.73, 60.29,52.86,51.42,51.07,50.27,29.46,27.01.ESI-HRMS:m / _{zcalcdfor C39H40N5O14} [M+H] ⁺ : _802.2513 ;found: _802.2586 .

15. Synthesis: (R)-4'-(2"-(2"'-(N-methyl,N-Cbz)amino)acetamido-3"-hydroxy)propionamido-4'-deoxy- α-D-uridine glucuronide (compound 21)

The chemical reaction equation is:

Compound 20 (200 mg, 0.25 mmol) was dissolved in CH ₃ OH (5 mL), and an aqueous solution (3 mL) of LiOH·H ₂ O (41.9 mg, 1.00 mmol) was added dropwise at 0°C. After stirring at 0°C for 3 hours, the starting material was monitored by TLC for completion. AcOH was added dropwise to adjust the pH of the solution to 2. The reaction solution was concentrated and subjected to HPLC preparation to obtain a white solid: compound 21 (43.3 mg, 30%). ¹ H NMR (400MHz, D ₂ O) δ 7.74 (d, J=7.2 Hz, 1H), 7.40-7.16 (m, 5H), 5.80 (d, J=7.6 Hz, 1H), 5.56-5.42 (m ,1H),5.17–4.90(m,2H),4.32(d,J=34.1Hz,1H), 4.02–3.87(m,2H),3.85–3.74(m,2H),3.72–3.52(m,3H _a ^_ 67.89, 61.48, 55.55, 53.08, 51.59, 35.94. ESI-HRMS: m/z calcd for C ₂₄ H ₃₀ N ₅ O ₁₂ [M+H] ⁺ : 580.1813; found: 580.1885.

16. Synthesis: (R)-4'-(2"-(2"'-(N-methyl)amino)acetamido-3"-hydroxy)propionamido-4'-deoxy-α-D- Uridine glucuronide (neoorthomycin)

The chemical reaction equation is:

Compound 21 (25.0 mg, 0.0431 mmol) and 10% Pd/C (10.0 mg) were added to EtOH (3 mL) and water (3 mL), and reacted at room temperature for 15 minutes under the presence of hydrogen, and the reaction was monitored by TLC completely. Filtration and concentration to obtain a white solid: compound 22, the target product neoorthomycin (19.2 mg, 100%). [α] ²⁰ _D +37.0 (c0.74, H ₂ O); ¹ HNMR (600 MHz, D ₂ O) δ 7.81 (d, J=7.9 Hz, 1H), 5.89 (d, J=7.9 Hz, 1H) ), 5.57(s, 1H), 4.48 (t, J=5.3Hz, 1H), 3.96(s, 2H), 3.83–3.77(m, 3H), 3.76–3.70(m, 2H), 2.64 (s, 3H); ¹³ CNMR (150MHz, D ₂ O) δ 174.0, 171.4, 168.1, 166.4, 152.3, 142.0, 103.1, 82.4, 77.9, 73.6, 71.6, 61.4, 55.7, 53.4, 50.2, 33.2; ESI-HRMS: m/ _zcalcd for _{C16H23N5NaO10} [M+Na] ⁺ : _468.1337 ; found: _468.1324 .

Claims (10)

1. compound 18 is characterized in that: name is: 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucuronic acid methyl ester uridine , the chemical structure is:

2. the preparation method of compound 18 described in claim 1, is characterized in that: specifically comprises the steps: 1), add 2',3'-di-O-benzoyl-4'-azido-4'-deoxy-α-D-glucouridine, referred to as: compound 16, and add CH together with TEMPO ₃ CN, then add iodobenzo acetate to complete the reaction, then add anhydrous EtOH to quench the reaction, concentrate to obtain a solid crude product, named: compound 17; 2), the compound 17 was dissolved in anhydrous CH ₃ OH, added H ₂ SO ₄ , the reaction was complete, then NaHCO ₃ was added to quench the reaction, and concentrated; the reaction solution was extracted with ethyl acetate, then dried, filtered, and decompressed. Concentration gave compound 18. 3. the preparation method of compound 18 according to claim 2 is characterized in that: the synthetic method of described compound 16 is: compound 14 and uracil are refluxed under TMSOTf/BSA/acetonitrile conditions to obtain compound 15, compound 15 The compound 16 was obtained by hydrolysis in Et ₃ N/CH ₃ OH; the names of the compounds 14 and 15 were respectively: compound 14: 1,6-di-O-acetyl-2,3-di-O-benzoyl -4-Azido-4-deoxy-α-D-glucose; Compound 15: 2',3'-Di-O-benzoyl-4'-azido-6'-O-acetyl- 4'-Deoxy-α-D-glucouridine. 4. Compound 19 synthesized by compound 18 is characterized in that: the name is: 2',3'-di-O-benzoyl-4'-amino-4'-deoxy-α-D-glucuronic acid methyl Esteruridine, the chemical structural formula is:

5. The preparation method of compound 19 according to claim 4, characterized in that: the compound 18 is reacted with SnCl ₂ ·H ₂ O, p-methylthiophenol, CHCl ₃ and Et ₃ N to separate and obtain compound 19 . 6. Compound 20 synthesized by compound 19 is characterized in that: the name is: (R)-2',3'-di-O-benzoyl-4'-(2"-(2"'-(N- Methyl, N-Cbz) amino) acetamido-3 "-hydroxyl) propionamido-4'-deoxy-α-D-glucuronide methyl uridine, the chemical structural formula is:

7. The preparation method of compound 20 according to claim 6, characterized in that: with the compound 19, (R)-2-[2'-(N-methyl, N-Cbz) amino]acetamido-3 -Hydroxypropionic acid is used as raw material, HATU is used as condensing agent, and 2,6-lutidine is used as base to fully react, and after extraction, washing, drying, filtration and concentration, compound 20 is isolated and obtained. 8. Compound 21 synthesized by compound 20 is characterized in that: the name is: (R)-4'-(2"-(2"'-(N-methyl, N-Cbz) amino)acetamido-3" -Hydroxy) propionamido-4'-deoxy-α-D-glucuronide uridine, the chemical structural formula is:

9 . The method for preparing compound 21 according to claim 8 , wherein the compound 21 is obtained by hydrolyzing the compound 20 in LiOH aqueous methanol solution at 0° C., concentrating and performing HPLC preparation. 10 . 10. a total synthesis method utilizing compound 21 described in claim 8 to synthesize neo-Othomycin, it is characterized in that: described compound 21 and content are that 10% Pd/C is added to EtOH and water, in the condition of hydrogen The reaction was complete at room temperature, filtered and concentrated to obtain neo-Othomycin.

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