JP4782393B2 - Method for producing sialic acid derivative and sialic acid derivative - Google Patents

Description

  The present invention relates to a method for producing a sialic acid derivative and a sialic acid derivative.

  A sugar chain, a molecule in which sugars are linked in a chain, has an important function in vivo, and is involved in recognition and interaction between cells. In particular, sialyl sugar chains having a sugar residue with a specific structure called sialic acid at the end of the sugar chain are receptors for influenza virus, and a lectin (sugar-binding protein) expressed when inflammation occurs in vascular endothelial cells. ) Is specifically recognized. Furthermore, a glycoprotein called erythropoietin (EPO), which is an erythropoietic factor, is rapidly metabolized when sialic acid is removed from the sugar chain.

  The biosynthesis of sugar chains is performed by repeating a sugar transfer reaction from a sugar nucleotide, which is a sugar donor, to a sugar acceptor by a glycosyltransferase. A sugar nucleotide is a monosaccharide that is energetically activated with a nucleotide having a phosphate, and a sugar transfer reaction occurs when the nucleotide acts as a leaving group. In addition, glycosyltransferases recognize sugar donors and sugar acceptors strictly and transfer sugar residues to sugar acceptors in a stereoselective and position-specific manner. In the case of sialic acid, the sugar nucleotide used in vivo is mainly cytidine-5'-monophosphate-sialic acid (CMP-sialic acid) in mammals.

Thus, CMP-sialic acid is an indispensable compound for enzymatically binding sialic acid to a sugar chain, and it is extremely useful to develop a chemical synthesis method that can be synthesized in large quantities.
Conventionally, the following method has been reported as a method for producing CMP-sialic acid. In this method, a phosphorylated cytidine derivative is first condensed with sialic acid having a free hydroxyl group only at the 2-position, and then trivalent phosphoric acid is oxidized to pentavalent. In this method, the amidite method is used as the best method for the cytidine derivative used in the condensation (see, for example, Patent Document 1).
International Publication Number WO95 / 25115

In Patent Document 1, a large number of steps are required for the preparation of phosphorylated cytidine derivatives. Therefore, a simple method for producing a sialic acid derivative with fewer steps is desired.
An object of the present invention is to provide a production method suitable for industrial production of a sialic acid derivative and a novel sialic acid derivative.

The present invention relates to the following method for producing a sialic acid derivative and a novel sialic acid derivative.
1. A method for producing a compound represented by formula (3), comprising oxidizing a compound represented by formula (4).

（式中、Ｒ^１は、アルキル基、アリル基、ベンジル基、ベンゾイル基、トリチル基、トシル基、ピバロイル基を示す。Ｒ^２は、アシル基、シリル基、アリル基、ベンジル基、トリチル基、アセタール基を示す。Ｒ^３は、アルキル基、アリル基、ベンジル基、トリチル基を示す。）

(Wherein R ¹ represents an alkyl group, an allyl group, a benzyl group, a benzoyl group, a trityl group, a tosyl group or a pivaloyl group. R ² represents an acyl group, a silyl group, an allyl group, a benzyl group, a trityl group, Represents an acetal group, and R ³ represents an alkyl group, an allyl group, a benzyl group, or a trityl group.)

（式中、Ｒ^１、Ｒ^２およびＲ^３は上記と同じ。）

(Wherein R ¹ , R ² and R ³ are the same as above)

2. A method for producing a compound represented by formula (2), wherein the compound represented by formula (3) is reduced.

（式中、Ｒ^２は、アシル基、シリル基、アリル基、ベンジル基、トリチル基、アセタール基を示す。Ｘ^＋、Ｙ^＋は、同一又は異なるカチオンを示す。）

(In the formula, R ² represents an acyl group, a silyl group, an allyl group, a benzyl group, a trityl group, or an acetal group. X ⁺ and Y ⁺ represent the same or different cations.)

3. A method for producing a compound represented by formula (2), comprising oxidizing a compound represented by formula (4) to produce a compound represented by formula (3) and then reducing the compound.
4). A method for producing a sialic acid derivative represented by formula (1), comprising reacting a compound represented by formula (2) with cytidine.

5. A method for producing a sialic acid derivative represented by formula (1), comprising reducing a compound represented by formula (3) to produce a compound represented by formula (2) and then reacting cytidine.
6). A compound represented by the formula (4) is oxidized to produce a compound represented by the formula (3) and then reduced to produce a compound represented by the formula (2), and then cytidine is reacted. A method for producing a sialic acid derivative represented by the formula (1):
7). Compound represented by formula (3).
8). A compound represented by formula (2).

  According to the present invention, it is possible to provide a simple method for producing a sialic acid derivative suitable for industrial production, in which cytidine can be used without protection and the number of steps can be greatly reduced.

The present invention provides a method for producing a sialic acid derivative and a novel sialic acid derivative.
In the method for producing a sialic acid derivative of the present invention, the starting material is sialic acid. Sialic acid may be synthesized or commercially available.

First, the carboxyl group of sialic acid and the hydroxyl groups other than the 2-position are protected. The carboxyl-protecting group R ¹ may be any group that can be removed by base treatment, and represents an alkyl group, an allyl group, a benzyl group, a benzoyl group, a trityl group, a tosyl group, or a pivaloyl group. Examples of the alkyl group include alkyl groups such as methyl, ethyl, and butyl. Examples of the benzyl group include benzyl groups such as benzyl, silylbenzyl, and p-acetoxybenzyl. Among these, an allyl group and a benzyl group are particularly preferable.
The protective group R ² for the hydroxyl group can be removed by base treatment like the carboxyl group, as long as it has a difference in reactivity during the deprotection reaction with the previously used protective group for the carboxylic acid. , A silyl group, an allyl group, a benzyl group, a trityl group, and an acetal group. Examples of the acyl group include unsubstituted or substituted acyl groups such as acetyl, monochloroacetyl, benzoyl, pivaloyl, and levonoyl. Examples of the silyl group include trimethylsilyl, t-butyldimethylsilyl, t-butyldiphenylsilyl, and triethylsilyl. Examples of the silyl group and benzyl group include benzyl groups such as benzyl group, silylbenzyl group, and p-acetoxybenzyl group, and examples of the acetal group include cyclic acetal groups such as a benzylidene group that protects two hydroxyl groups. be able to. An acyl group is preferable. More preferably, an acetyl group is good.
The protecting group R ^{3 for} phosphoric acid represents an alkyl group, an allyl group, a benzyl group, or a trityl group. Examples of the alkyl group and benzyl group include the same groups as those described above for R ¹ .

Introduction of a protecting group to a carboxyl group and a hydroxyl group can be performed by a known method. For example, the method of Hasegawa et al. (Hasegawa, A .; Ishida, H .; Kiso, MJ Carbohydrate Chem. 1993, 12 (3), 371-376) or Protecting groups in Organic Chemistry, John & S & W. , New York 1991, ISBN 0-471-62301-6, etc., can introduce a protecting group.
The resulting compound 5 can be represented by formula (5).

（式中、Ｒ^１およびＲ^２は上記と同じ。）
具体的に１例を示せば下記のように、シアル酸を炭酸セシウム塩にした後、ベンジルブロマイドあるいはベンジルジアゾメタンを用いてベンジルエステル化し、続いて無水酢酸、触媒量の６０％過塩素酸を用いて４,７,８,９位の水酸基をアセチル化し化合物５ａを得ることができる。エステル化反応は通常０℃〜１００℃の温度範囲で、１〜２４時間程度で行うのが好ましい。アセチル化等の水酸基の保護反応は通常０℃〜１００℃の温度範囲で、１〜２４時間程度で行うのが好ましい。

(In the formula, R ¹ and R ² are the same as above.)
Specifically, as shown below, sialic acid is converted to a cesium carbonate salt, then benzyl esterified with benzyl bromide or benzyldiazomethane, followed by acetic anhydride and a catalytic amount of 60% perchloric acid. Thus, the hydroxyl group at the 4, 7, 8, 9-position can be acetylated to obtain the compound 5a. The esterification reaction is usually preferably carried out in the temperature range of 0 ° C to 100 ° C for about 1 to 24 hours. The hydroxyl group protecting reaction such as acetylation is usually preferably carried out in the temperature range of 0 ° C. to 100 ° C. for about 1 to 24 hours.

Next, the hydroxyl group at the 2-position of the obtained compound 5 is reacted with protected phosphoric acid. This phosphorylation reaction is carried out in an organic solvent such as acetonitrile, dichloromethane, tetrahydrofuran, diethyl ether, benzene, dimethylformamide, preferably a polar organic solvent at a low temperature, preferably in the temperature range of −40 ° C. to 25 ° C. Done in the presence of The reaction is usually preferably performed in about 1 to 10 hours. For example, when the acid catalyst is added, the reaction is allowed to proceed at a low temperature, preferably −40 ° C. to −10 ° C., while gradually raising the temperature. The reaction is preferably carried out usually for about 1 to 6 hours. The acid catalyst that can be used here is preferably an organic acid, and for example, 1H-tetrazole, DL camphorsulfonic acid, pyridium-p-toluenesulfonate, p-toluenesulfonyl acid (tosylic acid), and the like can be used. 1H-tetrazole is preferable.
The resulting compound 4 can be represented by formula (4).

（式中、Ｒ^１、Ｒ^２およびＲ^３は上記と同じ。）

(Wherein R ¹ , R ² and R ³ are the same as above)

  Specifically, as shown below, the hydroxyl group at the 2-position of compound 5a can be phosphorylated using dibenzyl N, N-diethyl phosphoramidite and 1H-tetrazole to obtain compound 4a.

Subsequently, trivalent phosphoric acid of the obtained compound 4 is oxidized. This oxidation reaction is carried out in an organic solvent such as acetonitrile, dichloromethane, tetrahydrofuran, diethyl ether, benzene, dimethylformamide, preferably a polar organic solvent at a low temperature, preferably in the temperature range of −40 ° C. to 25 ° C. Done in the presence. Examples of the oxidizing agent that can be used here include hydrogen peroxide, m-chloroperbenzoic acid, t-butylhydroxyperoxide, iodine / pyridine and the like. T-butylhydroxyperoxide is preferable.
The resulting compound 3 can be represented by formula (3).

Ｒ^１、Ｒ^２およびＲ^３は上記と同じである。

R ¹ , R ² and R ³ are the same as above.

  Specifically, as an example, the compound 4a can be oxidized with trivalent phosphoric acid using t-butylhydroxyperoxide to obtain the compound 3a of pentavalent phosphoric acid.

And the protective group of phosphoric acid and carboxylic acid of the obtained compound 3 is deprotected. In this deprotection reaction, reduction is performed in an organic solvent such as 2-propanol and ethyl acetate in a temperature range of 0 ° C to 100 ° C. The reaction is preferably carried out usually for about 1 to 6 hours. As a reduction method that can be used here, there is catalytic reduction such as hydrogenation reaction using palladium / carbon as a catalyst, and a general reduction method should be used as long as it does not reduce other functional groups of compound 2. Can do.
The resulting compound 2 can be represented by formula (2).

（式中、Ｒ^２は上記と同じである。Ｘ^＋、Ｙ^＋は、同一又は異なるカチオンを示す。）

(In the formula, R ² is the same as above. X ⁺ and Y ⁺ represent the same or different cations.)

X ⁺ and Y ⁺ include, for example, alkali metal ions such as lithium ions, sodium ions and potassium ions, alkaline earth metal ions such as calcium ions, copper ions, silver ions, gold ions, magnesium ions and aluminum ions. Examples thereof include metal ions, ammonium ions of alkylamines such as ammonia, methylamine, ethylamine and butylamine, and ammonium ions such as aniline. In the case of ammonium ions, secondary ammonium ions such as dimethylamine and diethylamine, tertiary ammonium ions such as trimethylamine, triethylamine and tributylamine, and quaternary ammonium ions such as tetramethylamine and tetraethylamine may be used. As long as it is a cationic ion, any cationic ion may be used regardless of the type of metal, mineral, amine, and the valence of the ion.

  Specifically, the compound 3a can be catalytically reduced to deprotect the benzyl group of phosphoric acid and carboxylic acid and converted to the compound 2a. Compound 2 can also be prepared by phosphorylating the 2-position hydroxyl group of Compound 5 with phosphoric acid tris (triazolide) or phosphoric acid trihydrate, followed by debenzylation esterification by catalytic reduction such as hydrogenation reaction.

  Finally, compound 2 undergoes a condensation reaction with cytidine which is the key reaction of this synthetic route. This condensation reaction is carried out in the presence of a condensing agent in an organic solvent such as acetonitrile, dichloromethane, tetrahydrofuran, diethyl ether, benzene and dimethylformamide, preferably in a polar organic solvent at a temperature range of 0 ° C to 100 ° C. The reaction is preferably carried out usually for about 10 minutes to 6 hours. Examples of the condensing agent that can be used here include PyBop, HATU, HBTU, diisopropylcarbodiimide, and the like, and HOBt. HOBt and diisopropylcarbodiimide (DIPCI) are preferable. Following the condensation reaction, the protecting group is subsequently deprotected. This deprotection reaction is performed in the presence of a base compound. The base compound that can be used here is preferably a sodium hydroxide aqueous solution.

Specifically, as mentioned above, the reaction conditions are 1-10 equivalents in order to form an anhydride using hydroxybenzotriazole (HOBt) and efficiently attack the alcohol at the 5 ′ position of cytidine as described above. Of cytidine was added, and the reaction was carried out at 0 to 60 ° C., preferably at room temperature. Presence of compound 2a and cytidine, HOBt and diisopropylcarbodiimide (DIPCI) were added. In order to follow the reaction status in detail, the reaction is also followed by ³¹ P-NMR.

Then, immediately after the start of the reaction, a new signal began to be observed at −2.5 ppm in addition to the raw material −3.2 ppm signal (a). And the signal (b) became strongest after one hour. When the reaction was further traced, the signal (c) of the target acetyl derivative of CMP-sialic acid began to be observed at -4.2 ppm. The reaction was stopped at the time when the target peak intensity was highest ( ³¹ P NMR ratio: about 50%) (3 to 4 hours), and then an aqueous sodium hydroxide solution was added to deprotect the acetyl group of sialic acid. It was. Then, after leaving at room temperature for 15 hours, it was freeze-dried and purified by HPLC (monoQ) to obtain CMP-sialic acid 1 as a target product. Further, the signal (d) of −0.7 ppm observed after deacetylation is the 2-position phosphate of sialic acid. Further, since the signal appearing immediately after the reaction is neither a raw material nor a target product and cannot be isolated, it is considered that the signal is an anhydride signal in which the raw material is activated. The obtained compound was in good agreement with the standard CMP-sialic acid NMR signal. Moreover, sialyltransferase reaction was performed using the synthesized CMP-sialic acid, and it was confirmed that there was activity.

  However, in this case, there remains a possibility that HOBt directly activates phosphoric acid to give CMP-sialic acid without using carboxylic acid and phosphoric anhydride. Therefore, it was decided to carry out the same condensation using a 2-position phosphoric acid derivative of sialic acid in which the carboxylic acid was protected with a methyl ester. However, in this case, neither a signal that was considered to be an anhydride nor CMP-sialic acid was obtained as a result.

  This indicates that cytidine does not form a bond directly with phosphoric acid, but cytidine attacks after forming a carboxylic acid and phosphoric acid anhydride. From the above results, the adjacent synthesis of carboxylic acid and phosphoric acid, which has been estimated so far by studying a novel synthesis method of CMP-sialic acid, forms an interaction, that is, carboxylic acid phosphoric anhydride. It was confirmed that the hydroxyl group attacks phosphorus.

  By condensing a sialic acid phosphoric acid derivative with cytidine, a completely different CMP-sialic acid synthesis method could be established. In addition, since CMP-sialic acid is not generated when a carboxylic acid-protected raw material is used, this proved that the carboxylic acid of sialic acid and phosphoric acid at the 2-position bind to form an anhydride. . This also strongly suggests that this anhydride is also formed in the CMP-sialic acid molecule.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, it is not limited to these at all.

Synthesis example 1
Synthesis of Benzyl5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-β-D-glycero-D-galacto-2-nonulopyranononate (5) 5-acetamido-3,5- Dioxyxy-β-D-glycero-D-galacto-2-nonulopyranononate (526 mg, 1.7 mmol) was dissolved in methanol-water = 9: 1 (12 ml), cesium carbonate (305 mg, 0.85 mmol) was added, pH = 7 or less. After concentration under reduced pressure, the residue was azeotroped with dimethylformamide three times and dried with a vacuum desiccator. The residue was dissolved in dimethylformamide (6.0 ml), benzyl bromide (245 μl, 20.4 mmol) was added at room temperature under an argon stream, and the mixture was stirred overnight. After confirming disappearance of the raw materials, magnesium sulfate (anhydrous) was added after extraction with a saturated saline solution and then with a saturated aqueous sodium hydrogen carbonate solution. After concentration, the residue was purified by a silica gel column (ethyl acetate: methanol = 3: 2) to obtain a benzyl ester derivative (yield 680 mg, yield 99%).
Subsequently, the obtained compound (100.2 mg, 251 μmol) was dissolved in acetic anhydride (450 μl), acetic anhydride: perchloric acid = 450: 1 (450 μl) was added at −20 ° C. under an argon stream, and 2 at 20 ° C. Stir for hours. After confirming the completion of the reaction, the mixture was extracted with ethyl acetate and washed with saturated multistory water. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate: hexane = 5: 1) to obtain compound (5) (yield 84.5 mg, yield 60%).

¹ H-NMR (400 MHz, CDCl ₃ )
δ 7.40-7.30 (m, 5H, CH ₂ Ph ), 6.09 (d, 1H, J _{NH, 5} = 10.5 Hz, NH), 5.39 (dd, 1H, J ₇ , ₆ = 2.2 Hz, J _7,8 = 4.3 Hz, H-7), 5.31-5.13 (m, 5H, H-4, H-8, CH ₂ Ph), 4.54 (dd, 1H, J _{9a, 8} = 2.5 Hz, J _gem = 12.4 Hz, H-9a), 4.26 (dd, 1H, J _6,5 = 10.6 Hz, J _6,7 = 2.2 Hz, NH ), 4.15 (ddd, 1H, J _5,4 = J _5,6 = J _{5, NH} = 10.0 Hz, H-5), 4.01 (dd, 1H, J _{9b, 8} = 8.2 _{, J gem = 12.3Hz, H-} 9b), 2.30-2.20 (m, 2H, H-3 ax, H-3 eq), 2.13,2.07,1.99,1. 97, 1.89 (5s, 15H, Ac × 5

Synthesis example 2
Synthesis of Benzyl5-acetamido-4,7,8,9-tetra-O-acetyl-2-O- (dibenzylphosphityl) -3,5-dioxy-β-D-glycero-D-galacto-2-nonulopyranonate (4) Compound (5) (570 mg, 1.0 mmol) was dissolved in acetonitrile (11 ml), and N, N-diethyldiphenylphosphoramide (900 ml, 2.6 mmol) and 1H-tetrazole (210 mg, 3.0 mmol) were added at −20 ° C. under an argon stream. ) Was added and stirred for 30 minutes. After confirming disappearance of the raw materials, magnesium sulfate (anhydrous) was added after extraction with a saturated saline solution and then with a saturated aqueous sodium hydrogen carbonate solution. After concentration, the residue was purified by a silica gel column (ethyl acetate: hexane = 2: 1) to obtain compound (4) (yield 615 mg, yield 76%).

¹ H-NMR (400 MHz, CDCl ₃ )
δ 7.51-7.28 (m, 15H, CH ₂ Ph × 3), 5.6-5.1 (m, 5H, H-7, H-8, CH ₂ Ph × 3), 4.94 -4.83 (m, 4H, H- 4, CH 2 Ph × 3), 4.55 (dd, 1H, J 8,9a = 2.5Hz, J 9a, 9b = 12.4Hz, H-9a) 4.38 (d, 1H, J5 _{, NH} = 10.4 Hz, NH), 4.19 (dd, 1H, _{J8 , 9b} = 6.8 Hz, J9a, _9b = 12.4 Hz, H-9b ), 4.03 (ddd, 1H, J _4,5 = J _5,6 = 10.7 Hz, H-5), 3.75 (dd, 1H, J _5,6 = 10.7 Hz, J _6,7 = 1.9 Hz, H-6), 2.42 (dd, 1H, J _{3 eq, 3ax} = 13.0 Hz, J _{3 eq, 4} = 4.9 Hz, H-3 eq), 2.10, 2.09, 2 .02, 2.00, 1.82 ( s, 15H, Ac × 5), 2.05-2.02 (m, 1H, H-3ax)
³¹ P-NMR
δ-138 (s)

Example 1
Synthesis of Benzyl5-acetamido-4,7,8,9-tetra-O-acetyl-2-O- (dibenzylphosphoryl) -3,5-deoxy-β-D-glycero-D-galacto-2-nonopyranononate (3) Compound (4) (800 mg, 0.99 mmol) was dissolved in acetonitrile (11.2 ml), and 3.1 ml of t-butylhydroxyperoxide (manufactured by Aldrich) was added and stirred at −20 ° C. under an argon stream. After 30 minutes, dimethyl sulfide (2.2 ml, 30 mmol) was added and concentrated. The residue was purified by silica gel column (ethyl acetate: hexane = 5: 1) to obtain compound (3) (yield 740 mg, yield 90%).

¹ H-NMR (400 MHz, CDCl ₃ )
δ 7.36-7.26 (m, 15H, CH ₂ Ph × 3), 5.35-5.29 (m, 3H, CH ₂ Ph × 3), 5.12-4.89 (m, 7H , H-7, H-8, H-4, NH ₂ CH ₂ Ph × 3), 4.56 (dd, 1H, J ₈ , _9a = 2.5 Hz, J _{9a, 9b} = 12.4 Hz, 4.29 (Dd, 1H, J _8,9b = 7.4 Hz, H-9b), 4.16-4.11 (m, 2H, H-5, H-6), 2.59 (dd, 1H, J _{3eq , 3ax = 13.6Hz, J 3eq,} 3ax = 4.8Hz, H-3eq), 2.11,2.02,1.99,1.97,1.86 (5s, 15H, Ac × 5), 2.06-2.00 (m, 1H, H-3ax)

Example 2
Synthesis of 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dioxy-β-D-glycero-D-galacto-2-nonopyranonosonate 2-phosphate (2) Compound (3) (150 mg , 0.15 mmol) was dissolved in 2-propanol and n-butylamine (140 μl, 0.45 mmol) was added. Palladium / charcoal (15 mg) was added under an argon stream, and then reacted for 3 hours under a hydrogen stream. The palladium was filtered through activated carbon and concentrated. The residue was purified by a silica gel column (ethyl acetate: methanol: water = 10: 5: 1) to obtain compound (2) (yield 87 mg, 70%).

¹ H-NMR (400 MHz, D ₂ O)
δ 5.39 (dd, 1H, J _6,7 = 2.0 Hz, J _7,8 = 5.7 Hz, H-7), 5.30-5.22 (m, 2H, H-4, H- 8), 4.48 (dd, 1H, J ₈ , _9a = 2.7 Hz, J _{9a, 9b} = 12.5 Hz, H-9a), 4.37 (dd, 1H, J ₅ , ₆ = 10.6 Hz) , J _6,7 = _2.0 Hz, H-6), 4.28 (dd, 1H, J _{8 , 9b} = 5.7 Hz, J _{9a, 9b} = 12.5 Hz, H-9b), 3.86 ( _{ddd, 1H, J 5,4 = J} 5,6 = 10.6Hz, H-5), 2.57 (dd, 1H, J 3eq, 3ax = 13.30Hz, J 3eq, 4 = 5.1Hz, H -3 eq), 2.11, 2.06, 2.02, 1.97, 1.85 (5s, 15H, Ac × 5), 2.04-2.01 (m, 1H, H-3ax)
³¹ P-NMR
δ −4.47 (s)

Example 3
Synthesis of Cytidine-5′-yl 5-acetamido-3,5-dioxyxy-D-glycero-β-D-galacto-2-nonopyranosid-2 ″ -yl Phosphate (CMP-NeuAc) (1) Compound (2) A mixture of (25 mg, 30 μmol) and cytidine (72.5 mg, 300 μmol) was azeotroped with distilled N, N-dimethylformamide (DMF) 5 times each and dried in a desiccator overnight. The mixture was dissolved in distilled DMF (350 μl), and hydroxybenzotriazole (8.1 mg, 60 μmol) and diisopropylcarbodiimide (9.2 μl, 60 μmol) were added and stirred at room temperature under a stream of argon. After 4.5 hours, 0.2N aqueous sodium hydroxide (6.0 ml, 1.2 mmol) was added. After 15 hours, it was lyophilized. The residue was purified with a gel filtration column to obtain compound (1).

¹ H-NMR (400 MHz, D ₂ O)
δ 7.92 (d, 1H, J _5,6 = 7.6 Hz, H-6), 6.07 (d, 1H, J _6,5 = 7.6 Hz, H-5), 5.93 (d , 1H, J _{1 ', 2'} = 4.5Hz, H-1 '), 4.29-4.18 (m, 5H, H'-2, H-3', H-4 ', H-5) 'a, H-5'b), 4.09 (d, 1H, J _{7 ", 8"} = 9.7Hz, H-7 "), 4.02 (ddd, 1H, J _{4", 3 "eq} = 4.7 Hz, J _{4 ", 3" ax} = 11.4 Hz, J ₄ , ₅ = 10.5 Hz, H-4 "), 3.90 (dd, 1H, J _{5", 4 "} = J _{5" , 6 "} = 10.5Hz, H-5"), 3.87 (ddd, 1H, J _{8 ", 7"} = 9.7Hz, J _{8 ", 9" a} = 6.6Hz, J _{8 ", 9 "b = 2.4Hz, H-8} "), 3.82 (dd, 1H, J 9 "b, 9" a = 11.7Hz, J 9b ", _{"= 2.4Hz, H-9"} b), 3.57 (dd, 1H, J 9 "a, 9" b = 11.7Hz, J 9 "a, 8" = 6.6Hz, H-9 " a), 3.38 (d, 1H, J _{7 ″, 8 ″} = 9.7 Hz, H−7), 2.44 (dd, 1H, J _{3 ″ eq, 4 ″} = 4.7 Hz, J _gem = 13.4 Hz, H-3 ″ eq), 2.00 (s, 3H, Ac), 1.60 (ddd, 1H, J _{3 ″ ax, 4 ″} = 11.4 Hz, J _gem = 13.4 Hz, J _{3 "ax, P} = 5.6Hz, H-3" ax)
³¹ P-NMR (400 MHz, D ₂ O)
δ -4.46

Claims (8)

A method for producing a compound represented by formula (3), comprising oxidizing a compound represented by formula (4).

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. )

(Wherein R ¹ , R ² and R ³ are the same as above) A method for producing a compound represented by formula (2), wherein the compound represented by formula (3) is reduced.

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. )

(In the formula, R ² is the same as above. X ⁺ and Y ⁺ represent the same or different cations.) A method for producing a compound represented by formula (2), comprising oxidizing a compound represented by formula (4) to produce a compound represented by formula (3) and then reducing the compound.

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. )

(Wherein R ¹ , R ² and R ³ are the same as above)

(In the formula, R ² is the same as above. X ⁺ and Y ⁺ represent the same or different cations.) A method for producing a sialic acid derivative represented by formula (1), comprising reacting a compound represented by formula (2) with cytidine.

(In the formula, R ² represents an acyl group or a silyl group. X ⁺ and Y ⁺ represent the same or different cations.)

A method for producing a sialic acid derivative represented by formula (1), comprising reducing a compound represented by formula (3) to produce a compound represented by formula (2) and then reacting cytidine.

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. )

(In the formula, R ² is the same as above. X ⁺ and Y ⁺ represent the same or different cations.)

A compound represented by the formula (4) is oxidized to produce a compound represented by the formula (3) and then reduced to produce a compound represented by the formula (2), and then cytidine is reacted. A method for producing a sialic acid derivative represented by the formula (1):

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. )

(Wherein R ¹ , R ² and R ³ are the same as above)

(In the formula, R ² is the same as above. X ⁺ and Y ⁺ represent the same or different cations.)

Compound represented by formula (3).

(In the formula, R ¹ represents an allyl group, a benzyl group, or a trityl group. R ² represents an acyl group or a silyl group. R ³ represents an allyl group, a benzyl group, or a trityl group. ) A compound represented by formula (2).

(In the formula, R ² represents an acyl group or a silyl group. X ⁺ and Y ⁺ represent the same or different cations.)