JP7352596B2 - Method for producing catechin conjugate - Google Patents

Description

The present invention relates to a method for producing a catechin conjugate and an intermediate for producing the same.

Catechins contained in tea leaves are known to have various excellent physiologically active functions, such as suppressing cholesterol rise and burning body fat.

It is known that catechins absorbed into the body exist not only in a free state but also as conjugates such as glucuronide conjugates, sulfate conjugates, and methyl conjugates. Therefore, it is important to examine the pharmacokinetics and biological activity of such conjugates in exploring the usefulness of catechins. However, it is difficult to obtain a sufficient amount of such metabolites by directly isolating them from body fluids such as blood or urine, and it is necessary to synthesize them chemically.

Methods for chemically synthesizing conjugates of catechin or epicatechin include a method in which catechins are treated non-selectively with an excess amount of a conjugation reagent and the resulting product is separated, as well as a method using cheap bulk starting materials. A total synthesis method in which a catechin skeleton is constructed by coupling using catechin (e.g., Non-Patent Document 1, Patent Document 1), or a method in which catechin or epicatechin is used as a starting material to selectively protect the phenolic hydroxyl group and a specific site is protected. Semi-synthetic methods of conjugation exist. The total synthetic method requires a long number of synthesis steps and also requires the construction of an asymmetric center, while the semi-synthetic method poses the problem of selective protection and deprotection of hydroxyl groups.
For example, Non-Patent Document 2 discloses a method for producing a methyl conjugate of catechin by protecting the hydroxyl group of catechin with di-tert-butyldichlorosilane as shown in the following formula. However, in this method, the subsequent synthesis is performed as a mixture of the 3'-substituted product and the 4'-substituted product obtained in the reaction, and the problem is considered to be a lack of separability.

Tetrahedron Letters 2012, 53, 1501-1503 J. Chem. Soc., Perkin Trans. 1, 2002, 821-830

Special table 2014-522870 publication

The present invention relates to a method for efficiently producing a catechin conjugate by a semi-synthetic method, and to providing an intermediate for the production.

The present inventors investigated the chemical synthesis of catechin conjugates from catechin compounds such as catechin and epicatechin catechin, and found that the phenolic hydroxyl group was converted into a benzyl group ( Bn), the remaining hydroxyl group is protected with a benzyloxycarbonyl group (Cbz), and then the hydroxyl group at the 3' or 4' position (B ring) of the catechin compound is protected by a conjugation reaction. We found that conjugation can be carried out efficiently.

[In the formula, one of R ^1a and R ^2a is a hydrogen atom and the other is an allyl group, one of R ^1b and R ^2b is a benzyl group and the other is an allyl group, and R ^1c and R ^2c are One of them is a benzyl group and the other is a hydrogen atom, and one of R ^1d and R ^2d is a hydrogen atom and the other is a methyl group, glucuronosyl group, glucosyl group, or -SO ₃ M (where M is a hydrogen atom) , an alkali metal atom, an alkaline earth metal atom, or ammonium). Further, R ^1b and R ^2b correspond to R ^1a and R ^2a , R ^1c and R ^2c correspond to R ^1b and R ^2b , and R ^1d and R ^2d correspond to R ^1c and R ^2c , respectively. ]

That is, the present invention relates to the following 1) to 3).
1) Allylate the hydroxyl group at the 3' or 4' position of the catechin compound represented by the above formula (I) to obtain an allylated catechin compound (II), and then benzylate the phenolic hydroxyl group to form the formula (III) A method for producing an allylated catechin protected derivative represented by formula (IV), which comprises preparing a compound represented by formula (IV), and then benzyloxycarbonylating the remaining hydroxyl group.
2) The allyl group of the allylated catechin protected derivative represented by formula (IV) obtained by the method of 1) is removed to obtain the catechin protected derivative represented by formula (V), and then sulfated and methylated. A method for producing a catechin conjugate represented by formula (VI), which comprises subjecting it to a conjugation reaction selected from , glucuronidation and glucosylation, and subsequently removing a protecting group.
3) An allylated catechin protected derivative represented by the general formula (IV) or a catechin protected derivative represented by the general formula (V).

The catechin conjugate of the present invention and its production intermediate can be produced simply and efficiently.

Below, each step of the method for producing a catechin conjugate of the present invention will be explained.
In the method for producing a catechin conjugate of the present invention, the following formula (I) used as a starting material:

で表される化合物には、フラバノールの２位及び３位の不斉炭素原子に関する立体異性体（鏡像異性体、ジアステレオ異性体）の全てが包含される。すなわち、式（Ｉ）で表される化合物には、（＋）－カテキン（２Ｒ，３Ｓ）、（－）－カテキン（２Ｓ，３Ｒ）、（＋）－エピカテキン（２Ｓ，３Ｓ）、（－）－エピカテキン（２Ｒ，３Ｒ）が包含され、本発明においてはこれらを纏めてカテキン化合物（Ｉ）と称する。
また、慣例に従い、フラバノール骨格の二つのベンゼン環をＡ環及びＢ環（カテコール部分）とし、両者を結ぶ３つの炭素原子と酸素原子から構成される環をＣ環と呼ぶ。

The compound represented by the above includes all stereoisomers (enantiomers, diastereoisomers) regarding the asymmetric carbon atoms at the 2nd and 3rd positions of flavanol. That is, the compound represented by formula (I) includes (+)-catechin (2R, 3S), (-)-catechin (2S, 3R), (+)-epicatechin (2S, 3S), (- )-epicatechin (2R, 3R), which are collectively referred to as catechin compound (I) in the present invention.
Further, according to custom, the two benzene rings of the flavanol skeleton are referred to as ring A and ring B (catechol moiety), and the ring consisting of three carbon atoms and an oxygen atom connecting the two is referred to as ring C.

1. Process-1

[In the formula, one of R ^1a and R ^2a represents a hydrogen atom and the other represents an allyl group. ]

This step is a step in which the hydroxyl group at the 3'-position or 4'-position of the catechin compound (I) is allylated.
The allylating reagent used here is not particularly limited, but preferably includes allyl halides. As the allyl halide, preferably allyl bromide, allyl chloride, and allyl iodide are mentioned, and allyl bromide is more preferable.

When allyl halide is used as an allylation reagent, the amount of allyl halide compound to be used is 5 to 50 mol, preferably 10 to 30 mol, more preferably 17 to 22 mol, per 1 mol of catechin compound (1). It is a mole.

The solvent used in this reaction may be any solvent that does not adversely affect the allylation reaction, such as halogenated hydrocarbon solvents such as methylene chloride and chloroform; ether solvents such as diethyl ether, diisopropyl ether, THF, and dioxane; Examples include ketone solvents such as acetone and methyl ethyl ketone; aprotic polar solvents such as N,N-dimethylformamide (DMF); and mixed solvents thereof. Preferably, ketone solvents such as acetone and methyl ethyl ketone are used.

The allylation reaction is usually carried out under alkaline conditions. Examples of the alkaline reagent include alkali metal hydroxides and alkali metal carbonates, and preferably potassium hydroxide, sodium hydroxide, sodium carbonate, and potassium carbonate can be used. More preferred are potassium hydroxide and potassium carbonate, and more preferred is potassium carbonate.

The amount of alkaline reagent used is 1 to 10 mol, preferably 3 to 5 mol, per 1 mol of catechin compound (I).

The allylation reaction may be carried out in the presence of an activating agent, and examples of such activating agents include alkali metal iodides such as sodium iodide and potassium iodide.

The allylation reaction can be carried out usually at 0 to 70°C, preferably at 10 to 40°C, more preferably at 20 to 30°C.
The reaction time is usually preferably 1 to 48 hours, more preferably 18 to 24 hours.

The obtained allylated form (II) can be separated into 3' allylated form and 4' allylated form by preparative HPLC using a column packed with octadecylsilylated silica gel (ODS) or the like.

2. Process-2

[In the formula, one of R ^1a and R ^2a is a hydrogen atom and the other is an allyl group, one of R ^1b and R ^2b is a benzyl group and the other is an allyl group, and R ^1b and R ^2b are Corresponding to R ^1a and R ^2a , respectively. ]

Subsequently, the phenolic hydroxyl group of the allylated compound (II) obtained in the above step is benzylated to obtain compound (III).
Benzylation can be carried out according to or analogously to a known method. That is, it can be carried out by reacting the allylated compound (II) with a benzyl halide in the presence of a base.

The solvent may be any solvent that does not adversely affect the reaction, such as ketone solvents, ether solvents, ester solvents, aprotic polar solvents, halogenated hydrocarbon solvents, or mixed solvents thereof. Can be mentioned. Preferred are aprotic polar solvents such as tetrahydrofuran, acetone, acetonitrile, N,N-dimethylformamide, and dimethylsulfoxide, and more preferred is N,N-dimethylformamide.

As the base, known inorganic bases and organic bases can be used. Examples of inorganic bases include alkali metals, alkali metal hydrogen carbonates, alkali metal hydroxides, alkali metal carbonates, alkali metal lower (C _1-4 ) alkoxides, alkali metal hydrides (e.g., sodium hydride, potassium hydride). etc.) etc. Examples of organic bases include trialkylamines (for example, trimethylamine, triethylamine, N,N-diisopropylethylamine, etc.), pyridine, quinoline, piperidine, imidazole, picoline, 4-dimethylaminopyridine, N,N-dimethylaniline, N-methyl Morpholine, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4. 0] undec-7-ene (DBU) and the like. Furthermore, when these bases are in liquid form, they can also be used as a solvent. These bases may be used alone or in a mixture of two or more. Preferably it is an alkali metal hydride, more preferably sodium hydride.

The amount of the base used is usually 1 to 4.5 mol, preferably 2 to 4 mol, and more preferably 2.9 to 3.1 mol, per 1 mol of allylated compound (II).

Examples of the benzyl halide include benzyl chloride, benzyl bromide, and benzyl iodide. These may be used alone or in a mixture of two or more. Among these, benzyl bromide is preferred.
The amount of benzyl halide to be used is usually 1 to 4.5 mol, preferably 2 to 4 mol, more preferably 2.5 to 3.5 mol, even more preferably The amount is 3.1 to 3.3 moles.

The reaction temperature is not particularly limited, and the reaction is usually carried out under cooling, at room temperature, or under heating. The reaction is preferably carried out at a temperature of 0 to 50°C, more preferably 10 to 40°C, even more preferably 20 to 30°C, for 0.5 to 24 hours, preferably 1 to 2 hours.

3. Process-3

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group. ]

Subsequently, the hydroxyl group at the 3-position of compound (III) obtained in the above step is converted to benzyloxycarbonyl (referred to as "Cbz" or "Z") to obtain compound (IV). The compound (IV) is an allylated catechin protected derivative having a protecting group that is easily removed, and is a novel compound that has not been described in any literature and is useful as an intermediate in the production of catechin conjugates.

For Cbz conversion in this step, any currently known method can be employed.
Examples of Cbzation reagents include the Schotten-Baumann method using benzyl chloroformate (benzyloxycarbonyl chloride (Z-Cl)), p-nitrophenyl ester (Z-ONp), N-hydroxysuccinimide ester (Z- ONSu), preferably benzyl chloroformate.
The amount of Cbz-forming reagent to be used is usually 0.5 to 10 mol, preferably 1 to 5 mol, more preferably 1.5 to 2.5 mol, even more preferably 1.5 mol, per 1 mol of compound (III). The amount is 9 to 2.1 moles.

Reaction solvents include inert halogenated hydrocarbon solvents such as dichloromethane and chloroform; inert hydrocarbon solvents such as toluene; inert ether solvents such as ether and tetrahydrofuran; amides such as dimethylformamide and dimethylacetamide. ; Examples include nitriles such as acetonitrile.

The reaction is carried out in the presence of a base, and the bases used include trialkylamines (for example, trimethylamine, triethylamine, N,N-diisopropylethylamine, etc.), pyridine, quinoline, piperidine, imidazole, picoline, 4-dimethylamino Pyridine, N,N-dimethylaniline, N-methylmorpholine, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO ), organic bases such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and inorganic bases such as potassium carbonate.
The amount of the base used is usually 1 to 5 mol, preferably 1.5 to 2.5 mol, more preferably 1.9 to 2.1 mol, per 1 mol of compound (III).

The reaction temperature ranges from -20 to 60°C, preferably from 0°C to room temperature.
The reaction time is usually about 0.5 to 24 hours, preferably about 2 to 3 hours.

4. Process-4

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group, one of R ^1c and R ^2c represents a benzyl group and the other represents a hydrogen atom, and R ^1c and R ^2c are Corresponding to R ^1b and R ^2b , respectively. ]

The allyl group of the allylated catechin protected derivative (IV) obtained in the above step is removed to obtain the catechin protected derivative (V). The derivative (V) is also a new compound that has not been described in any literature.
Desorption of the allyl group is carried out, for example, in the presence of a palladium catalyst such as palladium acetate, tetrakis(triphenylphosphine)palladium(0), or trisdibenzylideneacetone dipalladium, using a hydrogen source such as formic acid or its ammonium salt, or a hydrogen source such as morpholine. This can be done by using nuclear reagents.
The amount of the catalyst used is preferably 0.05 to 1 mol, more preferably 0.1 to 0.5 mol, and more preferably 0.2 to 0.3 mol, per 1 mol of compound (IV). .
The amount of the hydrogen source and nucleophilic reagent such as morpholine to be used is preferably 0.5 to 5 mol, more preferably 1 to 3 mol, and even more preferably 1.5 to 5 mol, per 1 mol of compound (IV). It is 2.5 moles.
Examples of the solvent used in this step include ether solvents such as tetrahydrofuran and 1,4-dioxane.

The reaction is carried out by stirring the compound (IV) and the catalyst in a solvent and adding a hydrogen source and a nucleophilic reagent such as morpholine to the mixture, and the reaction temperature is 0 to 40°C, preferably 24 to 27°C. The reaction time is 0.5 to 5 hours, preferably 1 to 2 hours.

5. Process-5

[In the formula, one of R ^1c and R ^2c is a benzyl group and the other is a hydrogen atom, and R ^1d and R ^2d are one of a hydrogen atom and the other a methyl group, glucuronosyl group, glucosyl group, or -SO ₃ M (here, M represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium), and R ^1d and R ^2d correspond to R ^1c and R ^2c , respectively. ]

The conjugation of the catechin protected derivative (V) is sulfation, methylation, glucuronidation or glucosylation, and the conjugation of the catechin protected derivative (V) is with a known sulfate donor, methyl donor, glucuronide. It is carried out by reacting an acid donor or a glucose donor.
Examples of the sulfuric acid donor include neopentyl chlorosulfate, trichloroethyl chlorosulfate, 2,2,2-trichloroethoxy-sulfuryl-1,2-dimethylimidazolium triflate (2,2,2-trichloroethoxy-sulfuryl- 1,2-dimethylimidazolium triflate (SDIS) and the like.
As the glucuronic acid donor, 2,3,4-tri-O-acetyl-α-D-methylglucuronopyranosyl-1-(N-phenyl)-2,2,2-trifluoroacetimidate, 2,3,4-tri-O-acetyl-α-D-methylglucopyranosyl-1-(N-4-methoxyphenyl)-2,2,2-trifluoroacetimidate, 2,3,4 -tri-O-acetyl-α-D-methylglucuronopyranosyl-1-O-(2,2,2-trichloroacetimidate), acetobromo-α-D-glucuronic acid methyl ester, and the like.
As glucose donors, 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl-1-(N-phenyl)-2,2,2-trifluoroacetimidate, 2,3, Examples include 4,6-tetra-O-acetyl-α-D-gluclopyranosyl-1-O-(2,2,2-trichloroacetimidate) and α-acetobromoglucose.
Examples of the methyl donor include methylating agents such as methyl iodide, dimethyl sulfate, p-toluenesulfonic acid methyl ester, and methanesulfonic acid methyl ester.

For example, sulfation is preferably carried out by stirring the catechin protected derivative (V) and SDIS in an ether, chlorine, aprotic or mixed solvent in the presence of a base. It will be done. As a base, triethylamine, N,N-diisopropylethylamine, pyridine, imidazole, quinoline, picoline, 1-methylimidazole, 1,2-dimethylimidazole, 4-dimethylaminopyridine, N,N-dimethylaniline, N-methylmorpholine , 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0 ] Examples include tertiary amines such as undec-7-ene (DBU), preferably 1,2-dimethylimidazole.
The reaction temperature is usually about 23 to 27°C, and the reaction time is usually about 1 to 12 hours.

For glucuronidation, a method using methyl 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-α-D-glucuronate as a glucuronic acid donor is preferred; , catechin protected derivative (V) and 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)- in the presence of a Lewis acid and molecular sieves 4A in an aprotic or mixed solvent thereof. This is carried out by stirring methyl α-D-glucuronate. Lewis acids include aluminum (III) chloride, diethylaluminum chloride, nickel (II) chloride (hexahydrate), tin (IV) chloride (pentahydrate), titanium (IV) chloride, zinc chloride, and trifluorocarbon. Examples include ran-ether complexes, and preferably trifluoroborane-ether complexes. The reaction temperature is usually about 23 to 27°C, and the reaction time is usually about 1 to 24 hours.

For glucosylation, a method using 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl 2,2,2-trichloroacetimidate as a glucosyl donor is preferred; In a protic or mixed solvent, in the presence of a Lewis acid and molecular sieves 4A, catechin protected derivative (V) and 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl 2,2,2- This is done by stirring trichloroacetimidate. Lewis acids include aluminum(III) chloride, diethylaluminum chloride, nickel(II) chloride (hexahydrate), tin(IV) chloride (pentahydrate), titanium(IV) chloride, zinc chloride, and trifluorocarbons. Examples include ran-ether complexes, and preferably trifluoroborane-ether complexes. The reaction temperature is usually about 23 to 27°C, and the reaction time is usually about 1 to 24 hours.

Methylation can be carried out, for example, by reacting the catechin protected derivative (V) with a methylating agent and a base in an aprotic polar solvent at 0° C. to room temperature.
Here, as the methylating agent, it is preferable to use iodomethane, dimethyl sulfate, methyl trifluoromethanesulfonate, diazomethane, trimethylsilyldiazomethane, etc., and more preferably iodomethane, dimethyl sulfate, and methyl trifluoromethanesulfonate. As the aprotic polar solvent, N,N-dimethylformamide, dimethylsulfoxide or hexamethylphosphoric triamide, or mixtures thereof and mixtures thereof with inert solvents (for example, tetrahydrofuran, 1,2-dimethoxyethane, etc.) can be used. Can be mentioned.
Bases include, for example, alkali metals such as sodium and potassium; alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium tert-butoxide; carbonates such as sodium carbonate and potassium carbonate; sodium bicarbonate and bicarbonate; Bicarbonates such as potassium carbonate; metal hydroxides such as sodium hydroxide and potassium hydroxide; metal hydrides such as sodium hydride and potassium hydride, etc. can be used.

The reaction products of the catechin protected derivative (V) and the sulfuric acid donor, methyl donor, glucuronic acid donor or glucose donor obtained in this way may be treated with ester residues derived from each donor as necessary. The catechin conjugate (VI) is obtained by removing the protective groups such as the group and the hydroxyl protecting groups (benzyl group and benzyloxycarbonyl group) of the A ring and the C ring.

Examples of means for removing protective groups such as ester residues include hydrolysis reaction. The hydrolysis reaction can be carried out by bringing the reaction product into contact with water in an appropriate solvent in the presence of an acid or a base. Examples of acids that can be used include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, and phosphoric acid, and organic acids such as acetic acid, trifluoroacetic acid, formic acid, and p-toluenesulfonic acid. Examples of the base include metal hydroxides such as sodium hydroxide and barium hydroxide, carbonates such as sodium carbonate and potassium carbonate, and sodium acetate.
As the solvent, for example, water-miscible organic solvents such as ethanol, ethylene glycol dimethyl ether, tetrahydrofuran, and dioxane are used together with water.
The reaction is usually carried out at about 0 to 100°C, preferably room temperature to 50°C, for 0.5 to 3 hours, preferably 0.5 to 2 hours.

In addition, as a means for removing the hydroxyl protecting groups of the A ring and the C ring, hydrogenolysis in the presence of a hydrogenation catalyst can be mentioned. According to this method, the benzyl group and the benzyloxycarbonyl group are simultaneously removed. can be done. In addition, when SDIS is used as a sulfuric acid donor to form a TCE sulfate, it is possible to simultaneously eliminate the benzyl group, benzyloxycarbonyl group, and TCE group by hydrolysis in the presence of a hydrogenation catalyst. .

In the presence of a hydrogen source (hydrogen, formic acid or formic acids such as ammonium formate), in an appropriate solvent, in the presence of a hydrogenation catalyst, the catechin protected derivative (V), a sulfuric acid donor, a methyl donor, etc. , by stirring the reaction product with a glucuronic acid donor or a glucose donor.
Examples of the solvent include ether solvents such as diethyl ether, tetrahydrofuran, and dioxane, alcohol solvents such as methanol and ethanol, acidic solvents such as formic acid and acetic acid, and mixed solvents thereof.

Examples of hydrogenation catalysts include palladium catalysts such as palladium (II) hydroxide/carbon (Pd(OH) ₂ /C) and palladium/carbon (Pd/C), hydrogen-supported metal catalysts such as Raney nickel, and the like.

The amount of hydrogenation catalyst used is usually 1 to 300% by mass, preferably 5 to 200% by mass, more preferably 10 to 150% by mass, and even more preferably 15 to 100% by mass, based on the charged mass of compound (VI). %, more preferably 20 to 50% by mass.

The reaction temperature is usually about 23 to 27°C, and the reaction time is usually about 6 to 24 hours.

The target product in each reaction of the present invention can be isolated, if necessary, by purification methods commonly used in organic synthetic chemistry, such as filtration, washing, drying, recrystallization, various chromatography, distillation, etc. can.

1. Example 1 Production of sulfuric acid conjugate (1) Synthesis of compound 6 and compound 7

Under an argon atmosphere, compound 1 ((-)-epicatechin, Tokyo Kasei Co., Ltd.) (500 mg, 1.7 mmol) and potassium carbonate (1 g, 7.3 mmol) were added to a 200 mL round-bottomed flask, and then acetone (33 mL) was added. The mixture was added and stirred to obtain a clear solution. Subsequently, allyl bromide (2.82 mL, 33 mmol) was added, and the mixture was stirred at room temperature for 20 hours. After the reaction, the mixed solution was filtered, washed with acetone, and the solvent was distilled off from the filtrate under reduced pressure using an evaporator. The obtained residue was purified by preparative HPLC to obtain Compound 6 (155 mg, 0.47 mmol, 27%) and Compound 7 (187 mg, 0.57 mmol, 33%) as white solids.
[Preparative conditions]
Preparative column: L-column ODS, size 20mm x 259mm 5μm
Eluent: A (0.1% formic acid water), B (methanol)
Flow rate: 20mL/min
Injection volume: 500μL
Temperature: 40℃
Detection wavelength: 280nm
Gradient condition B (%): 3% (5 minutes), 3 → 45% (10 minutes)

Compound 6:
^1H NMR (600MHz, MeOD): δ7.11 (d, J = 1.8Hz, 1H), 6.91 (dd, J = 8.2, 1.7Hz, 1H), 6.80 (d, J = 8.2Hz, 1H), 6.13-6.60 (m, 1H), 5.94 (d, J = 1.9Hz, 1H), 5.91 (d, J = 2.0Hz, 1H) , 5.40 (dd, J=19, 1.5Hz, 1H), 5.24 (dd, J=11, 1.4Hz, 1H), 4.85-4.85 (m, 1H), 4. 60 (d, J = 5.5Hz, 2H), 4.17-4.17 (m, 1H), 2.87 (dd, J = 17, 4.9Hz, 1H), 2.72 (dd, J =17, 2.9Hz, 1H)

^13C -NMR (150MHz, MeOD): δ158.03, 157.69, 157.32, 147.45, 147.31, 135.08, 132.18, 120.98, 117.97, 115.94, 113.70, 100.03, 96.36, 95.84, 79.90, 70.94, 67.53, 29.30

HRMS calcd. for C ₁₈ H ₁₉ O ₆ ⁺ [M+H] ⁺ :331.1176; found:331.1179

Compound 7:
^1H NMR (600MHz, MeOD): δ 7.01 (d, J = 1.6Hz, 1H), 6.90 (s, 1H), 6.89 (d, J = 1.8Hz, 1H), 6 .06-6.12 (m, 1H), 5.94 (d, J = 2.2Hz, 1H), 5.92 (d, J = 2.2Hz, 1H), 5.40 (dd, J = 17, 1.5Hz, 1H), 5.24 (dd, J = 10, 1.5Hz, 1H), 4.84-4.84 (m, 1H), 4.60 (dd, J = 5.2 , 1.5Hz, 2H), 4.18-4.19 (m, 1H), 2.86 (dd, J=18, 4.5Hz, 1H), 2.73 (dd, J=16, 2. 8Hz, 1H)

^13C -NMR (150MHz, MeOD): δ158.03, 157.70, 157.28, 147.54, 147.22, 135.17, 134.01, 119.11, 117.75, 115.42, 114.30, 99.99, 96.36, 95.83, 79.69, 70.97, 67.42, 29.27

HRMS calcd. for C ₁₈ H ₁₉ O ₆ ⁺ [M+H] ⁺ :331.1176; found:331.1179

(2) Synthesis of compounds 8 and 11

(2-1) Synthesis of Compound 8 Under an argon atmosphere, compound 6 (500 mg, 1.5 mmol) was placed in a 100 mL round bottom flask, and dehydrated N,N-dimethylformamide (10 mL) was added and stirred to obtain a clear solution. Ta. Subsequently, 60% oily sodium hydride (185 mg, 4.6 mmol) was added under cooling with -50 °C methanol solution, and after stirring for 15 minutes, benzyl bromide (585 μL, 4.9 mmol) was added dropwise, and an additional 45 Stir for a minute. Thereafter, the temperature was raised to room temperature and stirred for 1 hour. After the reaction, 1 mol/L hydrochloric acid was added while cooling in an ice bath to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with hexane-ethyl acetate (1:1, v/v), and the resulting organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The resulting residue was purified by silica gel chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)) to obtain Compound 8 (596 mg, 0.97 mmol, 64%) as a white amorphous.

^1H NMR (600MHz, acetone-d6): δ7.31-7.52 (m, 15H), 7.24 (d, J = 1.7Hz, 1H), 7.05 (dd, J = 8.0 , 1.7Hz, 1H), 7.03 (d, J = 8.3, 1H), 6.34 (d, J = 2.2, 1H), 6.21 (d, J = 2.4, 1H), 6.06-6.12 (m, 1H), 5.44 (ddt, J = 16, 3.5, 1.9Hz, 1H), 5.22 (ddt, J = 11, 3.1 , 1.6Hz, 1H), 5.14 (s, 2H), 5.11 (d, J = 4.52H), 5.07 (s, 2H), 4.99-4.99 (m, 1H ), 4.59 (ddd, J=5.2, 1.5, 1.5Hz, 2H), 4.26-4.29 (m, 1H), 2.94 (dd, J=17, 4. 7Hz, 1H), 2.85 (dd, J=16, 2.9Hz, 1H)

^13C -NMR (150MHz, acetone-d6): 159.343, 159.06, 156.81, 149.29, 149.13, 138.74, 138.52, 138.51, 134.95, 133. 68, 129.47, 129.28, 129.25, 129.20, 128.67, 128.55, 128.53, 128.50, 128.40, 128.30, 128.09, 120.62, 117.24, 114.95, 114.53, 102.56, 95.60, 94.09, 79.50, 71.45, 70.40, 66.52, 29.35

HRMS calcd. for C ₃₉ H ₃₇ O ₆ ⁺ [M+H] ⁺ :601.2585; found:601.2585

(2-2) Synthesis of Compound 11 Under an argon atmosphere, compound 7 (500 mg, 1.5 mmol) was placed in a 100 mL round bottom flask, and N,N-dimethylformamide (10 mL) was added and stirred to obtain a clear solution. . Subsequently, 60% oily sodium hydride (185 mg, 4.6 mmol) was added under cooling with -50 °C methanol solution, and after stirring for 15 minutes, benzyl bromide (585 μL, 4.9 mmol) was added dropwise, and an additional 45 Stir for a minute. Thereafter, the temperature was raised to room temperature and stirred for 1 hour. After the reaction, 1 mol/L hydrochloric acid was added while cooling in an ice bath to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by silica gel chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)) to obtain Compound 11 (600 mg, 1.00 mmol, 66%) as a white amorphous.

^1H NMR (600MHz, acetone-d6): δ7.32-7.52 (m, 16H), 7.07 (dd, J = 8.2, 1.3Hz, 1H), 6.98 (d, J = 8.3Hz, 1H), 6.35 (d, J = 2.2Hz, 1H), 6.20 (d, J = 2.2Hz, 1H), 6.06-6.12 (m, 1H) ,5.44(dd,J=17,1.8Hz,1H),5.22(dd,J=11,1.6Hz,1H),5.12(s,4H),5.08(s, 2H), 4.99 (s, 2H), 4.60 (ddd, J=5.2, 1.4, 1.4Hz, 2H), 4.27-4.27 (m, 1H), 2. 92-2.95 (m, 1H), 2.83-2.86 (m, 1H)

^13C -NMR (150MHz, acetone-d6): δ159.44, 159.06, 156.80, 149.31, 149.18, 138.65, 138.53, 135.05, 133.53, 129. 52, 129.29, 129.26, 129.17, 128.59, 128.56, 128.53, 128.52, 128.45, 128.39, 128.10, 120.82, 117.12, 114.85, 114.70, 102.56, 95.60, 94.09, 79.49, 71.57, 70.41, 70.34, 66.53, 29.33

HRMS calcd. for C ₃₉ H ₃₇ O ₆ ⁺ [M+H] ⁺ :601.2585;found:601.2585

(3) (2R,3R)-2-(3'-(Allyloxy)-4'-(benzyloxy)phenyl)-5,7-bis(benzyloxy)chroman-3-yl benzyl carbonate (compound 9) and (2R ,3R)-2-(4'-(Allyloxy)-3'-(benzyloxy)phenyl)-5,7-bis(benzyloxy)chroman-3-yl benzyl carbonate (compound 12)

(3-1) Synthesis of Compound 9 Under an argon atmosphere, compound 8 (550 mg, 0.92 mmol) and N,N-dimethylaminopyridine (230 mg, 1.88 mmol) were placed in a 100 mL round bottom flask, and dehydrated dichloromethane (20 mL) was added. was added and stirred to obtain a clear solution. Subsequently, benzyl chloroformate (264 μL, 1.88 mmol) and diazabicycloundecene (291 μL, 1.88 mmol) were sequentially added under cooling in an ice bath, and the mixture was stirred for 16 hours. After the reaction, the reaction solution was diluted with ethyl acetate (20 mL), and then 1 mol/L hydrochloric acid was added while cooling in an ice bath to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by silica gel chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)) to obtain Compound 9 (700 mg, 0.92 mmol, 100%) as a white amorphous.

^1H NMR (600MHz, DMSO-d6): δ7.30-7.46 (m, 20H), 7.08 (d, J = 2.1Hz, 1H), 7.04 (d, J = 8.4 , Hz, 1H), 6.96 (dd, J=8.5, 1.9Hz, 1H), 6.38. (d, J=2.3Hz, 1H), 6.23 (d, J=2.4Hz, 1H), 5.96-6.03 (m, 1H), 5.34 (ddt, J=17, 3.4, 1.7Hz, 1H), 5.24-5.25 (m, 1H), 5.19 (ddt, J=11, 3.1, 1.3Hz, 1H), 5.15-5 .15 (m, 1H), 5.10 (s, 4H), 5.05 (s, 2H), 4.98-4.98 (m, 2H), 4.51 (ddd, J=13,5 .3, 1.3Hz, 1H), 4.46 (ddd, J=13, 5.2, 1.4Hz, 1H), 3.04 (dd, J=18, 4.8Hz, 1H), 2. 86-2.83 (m, 1H)

^13C -NMR (150MHz, DMSO-d6): δ158.25, 157.42, 155.05, 153.94, 147.83, 147.66, 137.23, 137.14, 137.11, 135. 31,133.70,130.46,128.53,128.49,128.47,128.33,127.92,127.86,127.70,127.64,127.36,119.34, 117.45, 113.56, 112.46, 99.97, 94.70, 93.92, 76.05, 71.53, 69.90, 69.35, 69.34, 69.10, 68. 93,25.50

HRMS calcd. for C ₄₇ H ₄₃ O ₈ ⁺ [M+H] ⁺ :735.2952;found:735.2978

(3-2) Synthesis of Compound 12 Under an argon atmosphere, compound 11 (570 mg, 0.95 mmol) and N,N-dimethylaminopyridine (238 mg, 1.94 mmol) were placed in a 100 mL round bottom flask, and dehydrated dichloromethane (20 mL) was added. was added and stirred to obtain a clear solution. Subsequently, benzyl chloroformate (275 μL, 1.94 mmol) and diazabicycloundecene (300 μL, 1.94 mmol) were sequentially added under cooling in an ice bath, and the mixture was stirred for 16 hours. After the reaction, the reaction solution was diluted with ethyl acetate (40 mL), and 1 mol/L hydrochloric acid was added while cooling in an ice bath to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with hexane-ethyl acetate (1:1, v/v), and the resulting organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by silica gel chromatography (elution solvent: chloroform-ethyl acetate (9:1, v/v)) to obtain Compound 12 (734 mg, 0.92 mmol, 92%) as a white amorphous.

^1H NMR (600MHz, DMSO-d6): δ7.18-7.43 (m, 21H), 6.08-6.98 (m, 2H), 6.39 (d, J = 2.2Hz, 1H ), 6.22 (d, J = 2.2Hz, 1H), 6.01-6.08 (m, 1H), 5.40 (ddt, J = 17, 3.4, 1.6Hz, 1H) , 5.23-5.25 (m, 2H), 5.16-5.16 (m, 1H), 5.10 (s, 2H), 5.05 (s, 2H), 5.03 (d , J=12Hz, 1H), 4.99-5.00 (m, 2H), 4.96 (d, J=12Hz, 1H), 4.56-4.57 (m, 2H), 3.05 (dd, J=18, 4.7Hz, 1H), 2.84-2.87 (m, 1H)

^13C -NMR (150MHz, DMSO-d6): δ158.25, 157.43, 155.05, 153.95, 147.80, 137.14, 137.11, 137.06, 135.49, 135. 30,133.90,130.37,128.56,128.53,128.49,128.43,127.90,127.72,127.68,127.36,119.50,117.34, 113.41, 112.64, 99.98, 94.70, 93.92, 76.05, 71.53, 70.21, 69.36, 69.34, 69.08, 68.95, 25. 49

HRMS calcd. for C ₄₇ H ₄₃ O ₈ ⁺ [M+H] ⁺ :735.2952;found:735.2978

(4) (2R,3R)-2-(4'-(Benzyloxy)-3'-(hydroxy)phenyl)-5,7-bis(benzyloxy)chroman-3-yl benzyl carbonate compound 10), and (2R ,3R)-2-(3'-(Benzyloxy)-4'-(hydroxy)phenyl)-5,7-bis(benzyloxy)chroman-3-yl benzyl carbonate
Synthesis of (compound 13)

(4-1) Synthesis of Compound 10 Under an argon atmosphere, compound 9 (690 mg, 0.94 mmol) and tetrakistriphenylphosphine palladium (271 mg, 0.23 mmol) were placed in a 100 mL round bottom flask, and dehydrated tetrahydrofuran (10 mL) was added. Stirring gave a clear solution. Subsequently, morpholine (168 μL, 1.88 mmol) was added at room temperature and stirred for 30 minutes. After the reaction, the reaction solution was diluted with ethyl acetate (20 mL), and 1 mol/L hydrochloric acid was added to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was subjected to silica gel chromatography (elution solvent: chloroform-methanol (99:1, v/v)) and preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)). )) to obtain Compound 10 (465 mg, 0.86 mmol, 91%) as a white amorphous.

^1H NMR (600MHz, acetone-d6): δ7.26-7.52 (m, 20H), 7.09 (d, J = 2.1Hz, 1H), 7.01 (d, J = 8.4Hz , 1H), 6.93 (dd, J=8.3, 2.0Hz, 1H), 6.37 (d, J=2.3Hz, 1H), 6.24. (d, J=2.2Hz, 1H), 5.35-5.37 (m, 1H), 5.15 (s, 3H), 5.11-5.12 (m, 2H), 5.08 (s, 2H), 5.01-5.02 (m, 2H), 3.11 (dd, J=18, 4.0Hz, 1H), 2.99 (dd, J=18, 1.3Hz, 1H)

^13C -NMR (150MHz, acetone-d6): δ159.76, 158.82, 156.52, 155.34, 147.49, 147.14, 138.41, 138.31, 138.14, 136. 71,132.22,129.31,129.28,129.26,129.23,128.99,128.75,128.72,128.69,128.60,128.58,128.42, 128.15, 118.62, 114.97, 113.59, 101.16, 95.60, 94.51, 77.57, 72.77, 71.28, 70.52, 70.47, 69. 78, 26.61

HRMS calcd. for C ₄₄ H ₃₉ O ₈ ⁺ [M+H] ⁺ :695.2639; found:695.2669

(4-2) Synthesis of Compound 13 Under an argon atmosphere, compound 12 (660 mg, 0.90 mmol) and tetrakistriphenylphosphine palladium (260 mg, 0.22 mmol) were placed in a 100 mL round bottom flask, and dehydrated tetrahydrofuran (10 mL) was added. Stirring gave a clear solution. Subsequently, morpholine (161 μL, 1.80 mmol) was added at room temperature and stirred for 30 minutes. After the reaction, the reaction solution was diluted with ethyl acetate (20 mL), and 1 mol/L hydrochloric acid was added to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was subjected to silica gel chromatography (elution solvent: chloroform-methanol (99:1, v/v)) and preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)). ) to obtain Compound 13 (530 mg, 0.76 mmol, 85%) as a white amorphous.

^1H NMR (600MHz, acetone-d6): δ7.24-7.43 (m, 21H), 6.99 (dd, J = 8.2, 1.9Hz, 1H), 6.85 (d, J = 8.1Hz, 1H), 6.38 (d, J = 2.3Hz, 1H), 6.23 (d, J = 2.3Hz, 1H), 5.35-5.36 (m, 1H) , 5.16-5.16 (m, 1H), 5.12-5.13 (m, 2H), 5.08 (s, 2H), 5.02-5.07 (m, 4H), 3 .11 (dd, J=18, 4.5Hz, 1H), 3.01 (dd, J=18, 1.6Hz, 1H)

^13C -NMR (150MHz, acetone-d6): δ 159.75, 158.83, 156.56, 155.35, 147.63, 147.27, 138.40, 138.31, 137.95, 136 .63, 130.31, 129.32, 129.29, 129.27, 129.18, 129.04, 128.89, 128.76, 128.72, 128.61, 128.59, 128.41 , 128.16, 120.91, 115.87, 112.92, 101.14, 95.64, 94.62, 77.80, 72.84, 71.51, 70.53, 70.47, 69 .87, 26.63

HRMS calcd. for C ₄₄ H ₃₉ O ₈ ⁺ [M+H] ⁺ :695.2639;found:695.2669

(5) Synthesis of compounds 14 and 15

(5-1) Synthesis of Compound 14 Under an argon atmosphere, compound 10 (90 mg, 0.13 mmol) and SDIS (119 mg, 0.26 mmol) were placed in a 100 mL round bottom flask, and dehydrated dichloromethane (2.5 mL) was added and stirred. , a clear solution was obtained. Subsequently, 1,2-dimethylimidazole (25 mg, 0.26 mmol) was added at room temperature and stirred for 19 hours. After the reaction, the reaction mixture was diluted with ethyl acetate (5 mL) and water was added to stop the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by preparative thin layer chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)) to obtain Compound 14 (90 mg, 0.10 mmol, 77%) as a white amorphous. Ta.

^1H NMR (600MHz, acetone-d6): δ7.71 (d, J = 2.2Hz, 1H), 7.58 (d, J = 7.1Hz, 1H), 7.53 (dd, J = 8 .8, 2.1Hz, 1H), 7.26-7.48 (m, 20H), 6.39 (d, J = 2.2Hz, 1H), 6.26 (d, J = 2.3Hz, 1H), 5.43-5.44 (m, 1H), 5.31-5.31 (m, 1H), 5.28 (s, 2H), 5.11-5.12 (m, 2H) , 5.08 (s, 2H), 5.01 (s, 2H), 4.98-4.98 (m, 2H), 3.12 (dd, J=18, 4.4Hz, 1H), 3 .03 (dd, J=18, 1.3Hz, 1H)

^13C -NMR (150MHz, acetone-d6): δ159.80, 158.81, 156.11, 155.22, 151.02, 139.32, 138.32, 138.24, 137.06, 136. 58, 132.31, 129.59, 129.31, 129.28, 129.19, 129.07, 128.88, 128.85, 128.62, 128.60, 128.40, 128.17, 128.08, 122.43, 115.25, 101.05, 95.55, 94.76, 93.59, 81.09, 79.18, 76.78, 72.40, 71.67, 70. 56, 70.50, 69.97, 26.45

HRMS calcd. for C ₄₆ H ₄₀ C ₁₃ O ₁₁ S ⁺ [M+H] ⁺ :905.1351;found:905.1407

(5-2) Synthesis of Compound 15 Under an argon atmosphere, compound 10 (100 mg, 0.14 mmol) and SDIS (132 mg, 0.29 mmol) were placed in a 100 mL round bottom flask, and dehydrated dichloromethane (2.5 mL) was added and stirred. , a clear solution was obtained. Subsequently, 1,2-dimethylimidazole (28 mg, 0.29 mmol) was added at room temperature and stirred for 19 hours. After the reaction, the reaction mixture was diluted with ethyl acetate (5 mL) and water was added to stop the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (3:1, v/v)) to obtain compound 15 (104 mg, 0.11 mmol, 79%) as a white amorphous. I got it.

^1H NMR (600MHz, acetone-d6): δ7.24-7.56 (m, 23H), 6.41 (d, J = 2.3Hz, 1H), 6.27 (d, J = 2.2Hz , 1H), 5.47-5.47 (m, 1H), 5.33-5.33 (m, 1H), 5.22 (d, J = 12Hz, 1H), 5.15 (d, J = 11Hz, 1H), 5.12-5.13 (m, 2H), 5.09 (s, 2H), 5.01-5.02 (m, 2H), 5.00 (s, 2H), 3.13 (dd, J=18, 4.6Hz, 1H), 3.05 (dd, J=18, 1.3Hz, 1H)

^13C -NMR (150MHz, acetone-d6): δ159.81, 158.81, 156.02, 155.19, 151.17, 140.33, 139.11, 138.32, 138.24, 136. 88, 136.47, 129.57, 129.33, 129.32, 129.28, 129.24, 129.15, 129.03, 128.88, 128.64, 128.62, 128.42, 128.18, 123.70, 120.29, 114.06, 101.06, 95.67, 94.77, 93.62, 81.03, 77.21, 72.38, 71.81, 70. 58, 70.50, 70.04, 26.43

HRMS calcd. for C ₄₆ H ₄₀ C ₁₃ O ₁₁ S ⁺ [M+H] ⁺ :905.1351;found:905.1407

(6) 2-Hydroxy-5-((2'R,3'R)-3',5',7'-trihydroxychroman-2'-yl)phenyl ammonium sulfate (compound 2) and 2-Hydroxy-4- Synthesis of ((2'R,3'R)-3',5',7'-trihydroxychroman-2'-yl)phenyl ammonium sulfate (compound 3)

(6-1) Synthesis of Compound 2 Under an argon atmosphere, compound 14 (87 mg, 0.10 mmol) and ammonium formate (64 mg, 1.02 mmol) were placed in a 50 mL round bottom flask, and a tetrahydrofuran-methanol mixture (8 mL, 3: 1) was added to obtain a clear solution. Subsequently, palladium on carbon (17 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 4 hours. reaction,. for C ₁₅ H ₁₅ O ₉ S ⁺ [M+H] ⁺ :371.0431;found:371.0426

(6-1) Synthesis of Compound 3 Under an argon atmosphere, compound 15 (98 mg, 0.11 mmol) and ammonium formate (72 mg, 1.15 mmol) were placed in a 50 mL round bottom flask, and a tetrahydrofuran-methanol mixture (8 mL, 3: 1) was added and stirred to obtain a clear solution. Subsequently, palladium on carbon (19 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 4 hours. After the reaction, the palladium on carbon was filtered, washed with a tetrahydrofuran-methanol mixture (32 mL, 3:1), and the solvent was distilled off under reduced pressure from the resulting organic layer using an evaporator. The obtained residue was purified by preparative reverse phase thin layer chromatography (elution solvent: water-methanol (9:1, v/v)) to obtain a white solid. The obtained solid was purified by preparative HPLC to obtain Compound 3 (28 mg, 73 μmol, 61%) as a white solid.

[Preparative conditions]
Preparative column: L-column ODS, size 20mm x 259mm 5μm
Eluent: A (10mM ammonium acetate aqueous solution), B (acetonitrile)
Flow rate: 20mL/min
Injection volume: 500μL
Temperature: 40℃
Detection wavelength: 280nm
Gradient condition B (%): 10% (5 minutes), 10 → 30% (8 minutes)

^1H NMR (600MHz, MeOD): δ7.27 (d, J = 8.3Hz, 1H), 7.08 (d, J = 2.0Hz, 1H), 6.93 (dd, J = 8.5 , 2.2Hz, 1H), 5.93-5.93 (m, 2H), 4.89-4.89 (m, 1H), 4.20-4.21 (m, 1H), 2.87 (dd, J=16, 4.7Hz, 1H), 2.74 (dd, J=17, 2.3Hz, 1H)

^13C -NMR (150MHz, MeOD): δ158.03, 157.69, 157.14, 150.20, 140.63, 138.93, 123.61, 119.05, 116.89, 100.00, 96.42, 95.85, 79.53, 67.42, 29.18

HRMS calcd. for C ₁₅ H ₁₅ O ₉ S ⁺ [M+H] ⁺ :371.0431;found:371.0434

Example 2 Production of glucuronide conjugate (1) Synthesis of compounds 16 and 17

(1-1) Synthesis of Compound 16 Under an argon atmosphere, compound 10 (100 mg, 0.14 mmol) and 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl) were placed in a 50 mL round bottom flask. Methyl -α-D-glucuronate (207 mg, 0.43 mmol) and molecular sieves 4 Å (500 mg) were taken, and dehydrated dichloromethane (10 mL) was added and stirred to obtain a clear solution. Subsequently, trifluoroborane-ether complex (365 μL, 8.64 mmol) was added at 0° C., then the mixture was heated to room temperature and stirred for 18 hours. After the reaction, the reaction mixture was diluted with ethyl acetate (20 mL) and water was added to stop the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was roughly purified by preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (2:1, v/v)) to obtain a mixture (88 mg) as a white amorphous.

(1-2) Synthesis of Compound 17 Under an argon atmosphere, compound 10 (100 mg, 0.14 mmol) and 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl) were placed in a 50 mL round bottom flask. Methyl -α-D-glucuronate (207 mg, 0.43 mmol) and molecular sieves 4 Å (500 mg) were taken, and dehydrated dichloromethane (10 mL) was added and stirred to obtain a clear solution. Subsequently, trifluoroborane-ether complex (365 μL, 8.64 mmol) was added at 0° C., then the mixture was heated to room temperature and stirred for 18 hours. After the reaction, the reaction mixture was diluted with ethyl acetate (20 mL) and water was added to stop the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was roughly purified by preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (2:1, v/v)) to obtain a mixture (74 mg) as a white amorphous.

(2) (2R, 3R, 4R, 5S, 6R)-3,4,5-Trihydroxy-6-(2-hydroxy-5-((2″R, 3″R)-3″, 5″, 7 ″-trihydroxychroman-2″-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid (compound 4) and (2R,3R,4R,5S,6R)-3,4,5-Trihydroxy-6-(2 '-hydroxy-4'-((2″R, 3″R)-3″, 5″, 7″-trihydroxychroman-2″-yl)phenoxy)tetrahydro-2H-pyran-2-carboxylic acid (compound 5) synthesis of

(2-1) Synthesis of Compound 4 The mixture (88 mg) obtained in the synthesis of Compound 16 was placed in a 100 mL round bottom flask, and a tetrahydrofuran-ethanol-purified aqueous solution (5 mL, 2:2:1) was added and stirred. A solution was obtained. Subsequently, 1N aqueous sodium hydroxide solution (1 mL) was added at room temperature, and the mixture was stirred for 30 minutes. After the reaction, Amberlyst (registered trademark) 15 (H) and acetic acid (200 μL) were added to make the reaction solution acidic to stop the reaction. Subsequently, the filtrate was filtered, and the solvent was distilled off under reduced pressure using an evaporator. A tetrahydrofuran-methanol-acetic acid solution (4.2 mL, 30:10:2) was added to the resulting residue under an argon atmosphere and stirred to obtain a clear liquid. Subsequently, palladium on carbon (20 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 21 hours. After the reaction, the palladium on carbon was filtered, washed with a tetrahydrofuran-methanol solution (12 mL, 3:1), and the solvent was distilled off under reduced pressure from the resulting organic layer using an evaporator. The obtained residue was purified by preparative HPLC to obtain Compound 4 (6.3 mg, 13 μmol, 9.3% (3-step yield)) as a white solid.

[Preparative conditions]
Preparative column: L-column ODS, size 20mm x 259mm 5μm
Eluent: A (0.1% formic acid aqueous solution), B (acetonitrile)
Flow rate: 20mL/min
Injection volume: 500μL
Temperature: 40℃
Detection wavelength: 280nm
Gradient condition B (%): 5 → 12% (5 minutes), 12% (15 minutes)

¹ H NMR (600 MHz, D ₂ O-acetone-d6 (9:1)): δ7.16 (s, 1H), 6.97 (d, J=8.2Hz, 1H), 6.83 (d, J = 8.1Hz, 1H), 5.94 (s, 1H), 5.92 (s, 1H), 4.95 (d, J = 7.4Hz, 1H), 4.86 (s, 1H) , 4.20 (s, 1H), 3.70 (d, J=8.5Hz, 1H), 3.45-3.54 (m, 3H), 2.77 (dd, J=17, 3. 8Hz, 1H), 2.69 (d, J=16Hz, 1H)

¹³ C-NMR (150 MHz, D ₂ O-acetone-d6 (9:1)): δ175.63, 155.69, 155.54, 155.49, 146.10, 144.98, 131.11, 122 .60, 116.77, 115.54, 101.52, 100.02, 96.32, 95.63, 78.39, 76.75, 75.59, 73.05, 72.13, 65.82 ,27.80

HRMS calcd. for _C21H22O12Na ⁺ [M+Na] ⁺ : _489.1003 ;found: _489.1006

(2-2) Synthesis of Compound 5 The mixture (74 mg) obtained in the synthesis of Compound 16 was placed in a 100 mL round-bottomed flask, and a tetrahydrofuran-ethanol-purified aqueous solution (5 mL, 2:2:1) was added and stirred. A solution was obtained. Subsequently, 1N aqueous sodium hydroxide solution (1 mL) was added at room temperature, and the mixture was stirred for 30 minutes. After the reaction, Amberlyst (R) 15 (H) and acetic acid (200 μL) were added to make the reaction solution acidic to stop the reaction. Subsequently, the filtrate was filtered, and the solvent was distilled off under reduced pressure using an evaporator. A tetrahydrofuran-methanol-acetic acid solution (4.2 mL, 30:10:2) was added to the resulting residue under an argon atmosphere and stirred to obtain a clear liquid. Subsequently, palladium on carbon (20 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 21 hours. After the reaction, the palladium on carbon was filtered, washed with a tetrahydrofuran-methanol mixture (12 mL, 3:1), and the resulting organic layer was distilled under reduced pressure using an evaporator. The obtained residue was purified by preparative HPLC to obtain Compound 5 (4.1 mg, 8.8 μmol, 6% (3-step yield)) as a white solid.

[Preparative conditions]
Preparative column: L-column ODS, size 20mm x 259mm 5μm
Eluent: A (0.1% formic acid aqueous solution), B (acetonitrile)
Flow rate: 20mL/min
Injection volume: 500μL
Temperature: 40℃
Detection wavelength: 280nm
Gradient condition B (%): 5 → 10% (5 minutes), 10% (15 minutes)

¹ H NMR (600 MHz, D ₂ O-acetone-d6 (9:1)): δ7.07 (d, J = 8.3 Hz, 1H), 6.93 (s, 1H), 6.87 (d, J = 8.4Hz, 1H), 5.94 (s, 1H), 5.94 (s, 1H), 4.94 (d, J = 9.0Hz, 1H), 4.83 (s, 1H) , 4.20 (s, 1H), 3.73 (d, J=9.0Hz, 1H), 3.46-3.55 (m, 3H), 2.77 (dd, J=16, 4. 2Hz, 1H), 2.61 (d, J=16Hz, 1H)

¹³ C-NMR (150 MHz, D ₂ O-acetone-d6 (9:1)): δ175.63, 156.00, 155.73, 155.52, 145.79, 144.68, 134.49, 119 .20, 117.03, 114.90, 101.52, 99.97, 96.23, 95.67, 78.27, 76.72, 75.59, 73.05, 72.13, 65.92 ,27.76

HRMS calcd. for _C21H22O12Na ⁺ [M+Na] ⁺ : _489.1003 ;found: _489.1023

Comparative Example Synthesis of a catechin sulfate conjugate was attempted from Compound 6 obtained in Example 1 (1) by the method shown in the reaction scheme below. The reaction conditions for each step are also shown.

<Reaction conditions>
(a) BnBr, NaH, DMF, 2 hours, room temperature, 81%
Compound 6 (216 mg, 0.65 mmol) was placed in a 50 mL round bottom flask under an argon atmosphere, and N,N-dimethylformamide (5 mL) was added and stirred to obtain a clear solution. Subsequently, 60% oily sodium hydride (131 mg, 3.2 mmol) was added under cooling with -50 °C methanol solution, and after stirring for 15 minutes, benzyl bromide (388 μL, 3.2 mmol) was added dropwise, and the temperature was allowed to rise to room temperature. The temperature was raised and the mixture was stirred for 2 hours. After the reaction, 1 mol/L hydrochloric acid was added while cooling in an ice bath to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by silica gel chromatography (elution solvent: hexane-ethyl acetate (6:1, v/v)) to obtain Compound 18 (366 mg, 0.53 mmol, 66%) as a white amorphous.

(b) Pd(Ph ₃ ) ₄ , Mor, THF, 30 minutes, room temperature, quant.
Under an argon atmosphere, compound 18 (350 mg, 0.50 mmol) and tetrakistriphenylphosphine palladium (292 mg, 0.25 mmol) were placed in a 100 mL round bottom flask, and dehydrated tetrahydrofuran (10 mL) was added and stirred to obtain a clear solution. . Subsequently, morpholine (91 μL, 1.00 mmol) was added at room temperature and stirred for 1 hour. After the reaction, the reaction solution was diluted with ethyl acetate (20 mL), and 1 mol/L hydrochloric acid was added to make the reaction solution acidic, thereby stopping the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by silica gel chromatography (elution solvent: hexane-ethyl acetate (5:1, v/v)) to obtain Compound 19 (330 mg, 0.50 mmol, quant.) as a white amorphous.

(c) SDIS, 1,2-diMeIm, DCM, 19 hours, room temperature, quant.
Compound 19 (71 mg, 0.10 mmol) and SDIS (1240 mg, 0.5 mmol) were placed in a 20 mL round bottom flask under an argon atmosphere, and dehydrated dichloromethane (3 mL) was added and stirred to obtain a clear solution. Subsequently, 1,2-dimethylimidazole (26 mg, 0.25 mmol) was added at room temperature and stirred for 1 hour. After the reaction, the reaction mixture was diluted with ethyl acetate (5 mL) and water was added to stop the reaction. Subsequently, the organic layer was extracted three times with ethyl acetate, and the obtained organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and then the solvent was distilled under reduced pressure using an evaporator. The obtained residue was purified by preparative normal phase thin layer chromatography (elution solvent: hexane-ethyl acetate (6:1, v/v)) to obtain compound 20 (86 mg, 0.10 mmol, quant.) as a white amorphous. I got it.

(d) Pd/C, FANH ₄ , H ₂ , 4 hours, room temperature. 61%
Under an argon atmosphere, compound 20 (43 mg, 55 μmol) and ammonium formate (56 mg, 0.55 mmol) were placed in a 50 mL round bottom flask, and a tetrahydrofuran-methanol mixture (8 mL, 3:1) was added and stirred to obtain a clear solution. Obtained. Subsequently, palladium on carbon (10 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 4 hours. After the reaction, the palladium on carbon was filtered, washed with a tetrahydrofuran-methanol mixture (32 mL, 3:1), and the solvent was distilled off under reduced pressure from the resulting organic layer using an evaporator. The obtained residue was purified by reverse phase preparative thin layer chromatography (elution solvent: water-methanol (9:1, v/v)) to obtain compound 14 (16 mg, 33 μmol, 61%) as a white amorphous. .

(e) Pd(OH) ₂ , H ₂ , THF/MeOH, 1 hour, room temperature Under argon atmosphere, compound 21 (16 mg, 33 μmol) was placed in a 50 mL round bottom flask, and a tetrahydrofuran-methanol mixture (8 mL, 3:1 ) was added and stirred to obtain a clear solution. Subsequently, palladium hydroxide (30 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 1 hour. After the reaction, the palladium hydroxide was filtered, washed with a tetrahydrofuran-methanol mixture (32 mL, 3:1), and the solvent was distilled off under reduced pressure from the resulting organic layer using an evaporator. When the obtained residue was analyzed by mass spectrometry, epicatechin was obtained.

(f) Pd(OH) ₂ , H ₂ , AcOEt, 30 minutes, room temperature Under argon atmosphere, compound 20 (219 mg, 0.28 mmol) was placed in a 50 mL round-bottomed flask, and ethyl acetate (10 mL) was added and stirred to give a clear solution. A solution was obtained. Subsequently, palladium hydroxide (109 mg) was added at room temperature, the inside of the flask was replaced with hydrogen, and the mixture was vigorously stirred for 30 minutes. After the reaction, the palladium hydroxide was filtered, washed with tetramethanol (40 mL), and the solvent was distilled off under reduced pressure from the resulting organic layer using an evaporator. When the obtained residue was analyzed by mass spectrometry, epicatechin was obtained.

That is, the benzyl group containing the 3-position hydroxyl group of compound 6 was protected, and then the allyl group was deprotected and a sulfuric acid unit was introduced to investigate deprotection. However, under normal deprotection conditions, the 3-position benzyl group Protection was difficult. Therefore, when more active palladium hydroxide was used, the sulfate group was eliminated and epicatechin was obtained. Similar results were also obtained when compound 20 was carried out under the conditions reported in the literature (J. Nat. Prod. 2013, 76, 157-169).

Claims (3)

The following formula (I):

The hydroxyl group at the 3' or 4' position of the catechin compound represented by is allylated to form the following formula (II):

[In the formula, one of R ^1a and R ^2a represents a hydrogen atom and the other represents an allyl group. ]
The phenolic hydroxyl group is then benzylated to form an allylated catechin compound represented by the following formula (III):

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group. ]
A compound represented by the following formula (IV) is obtained, and then the remaining hydroxyl group is benzyloxycarbonylated:

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group. ]
A method for producing an allylated catechin protected derivative represented by The following formula (IV) obtained by the method according to claim 1:

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group. ]
The allyl group of the allylated catechin protected derivative represented by is removed to form the following formula (V):

[In the formula, one of R ^1c and R ^2c represents a benzyl group and the other represents a hydrogen atom. ]
A catechin protected derivative represented by the following formula (VI) is then subjected to a conjugation reaction selected from sulfation, methylation, glucuronidation and glucosylation, and then the protecting group is removed:

[In the formula, one of R ^1d and R ^2d is a hydrogen atom and the other is a methyl group, glucuronosyl group, glucosyl group, or -SO ₃ M (here, M is a hydrogen atom, an alkali metal atom, an alkaline earth metal atom) Or indicates ammonium.]
A method for producing a catechin conjugate represented by A compound represented by the following general formula (IV) or a compound represented by the general formula (V).

[In the formula, one of R ^1b and R ^2b represents a benzyl group and the other represents an allyl group, and one of R ^1c and R ^2c represents a benzyl group and the other represents a hydrogen atom. ]