JP2001226394A - METHOD FOR PRODUCING 2'-DEOXY-beta-GUANOSINE AND ITS INTERMEDIATE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing 2'-deoxyguanosine, solving a conventional defect, having no restriction of feed amount. SOLUTION: 2'-Deoxyguanosine having high β selectivity is synthesized by using a specific 2'-deoxyguanosine derivative as an intermediate. Consequently a method for efficiently synthesizing a large amount of 2'-deoxyguanosine can be provided by improving βselectivity of 2'-deoxyguanosine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to 2'-deoxy-β-guanosine and derivatives thereof. For more information,
The present invention relates to a method for producing 2′-deoxy-β-guanosine and a salt thereof, a 2′-deoxy-β-guanosine derivative that is a precursor thereof, and a method for producing the same.

[0002] Nucleosides such as 2'-deoxy-β-guanosine are useful as pharmaceuticals and agrochemicals including anticancer agents and antiviral agents, and also useful as raw materials for antisense DNA and the like which have been recently developed. Compound.

[0003]

2. Description of the Related Art As a method for producing 2'-deoxyguanosine, for example, the following is known. (1) Naturally occurring DNA is enzymatically degraded and 2'-
A method for obtaining deoxyguanosine. (2) reacting the silylated nucleobase with 1-acetyl-2-deoxyribose, then removing the protecting group to remove 2'-
A method for obtaining deoxyguanosine. (Tetrahedron.Lett.
31 (31), 4437-4440 (1990)] (3) 6-amino-2,8-dichloropurine was converted to a silver salt and reacted with 3,5-diacetyl-1-chloro-2′-deoxyribose to give acetyl. A method for obtaining 2'-deoxyguanosine by removing the group and then converting the base moiety. [Ch
em. Ber. 93, 140-149 (1960)] (4) Synthesis of 2-acetylamino-6-chloropurine, reaction of this mercury salt with a 1-chloro-2'-deoxyribose derivative to give deoxyguanosine. And how to guide.
[J. Med. Chem. 6, 684-688 (1963)] (5) 2-Fluoro-6-O-benzylguanine and 1,
A method of reacting 3,5-triacetyl-2'-deoxyribose to convert a fluoro group to an amino group and deprotect the acetyl group to obtain 2'-deoxyguanosine. (J.
Org. Chem. 34 (7), 2160-2163 (1969)] Among the above methods, the method (1) of enzymatically decomposing naturally occurring DNA is limited in the availability of raw materials, and there is a limit to large-scale supply. is there. In the method (2), the ratio of β-isomer and α-isomer, which is the isomer, is β / α-form of 32/68, which is low in β-selectivity, and purification of β-form from this is inefficient.
In the methods (3) and (4), the total yield was 1.5
% And 4.4% are not satisfactory. In the method (5), 2-fluoro-6-O-benzylpurine as a raw material is obtained from 2-amino-6-O-benzylpurine in a yield of 49%, and further from this, 2'-yield in a yield of 14%. Deoxyguanosine is obtained. In addition to the unsatisfactory yield of this method, this method requires production equipment capable of continuously converting to hydrogen fluoride, resulting in high costs.

[0004]

As described above, there has been no method for producing 2'-deoxyguanosine which can be efficiently supplied in large quantities. The present invention provides an intermediate for efficiently producing 2′-deoxyguanosine without restriction on the supply amount, a method for producing the intermediate, and a method for producing 2′-deoxyguanosine using the intermediate.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that 3 ', 5'-diacyl-6-O-benzyl-2'-deoxyguanosine and 3', It has been found that 5'-diacyl-2'-deoxyguanosine is useful as a synthetic intermediate for 2'-deoxyguanosine. Furthermore, a method for producing these compounds and a method for producing 2′-deoxyguanosine from these compounds have been established, and the present invention has been completed.
That is, the present invention relates to [1] a general formula [1] [formula 11]

[0006]

[Formula 11]

(Wherein R1, R2 and R3 each independently represent a phenyl group which may be substituted) and a salt thereof, and [2] wherein R1 and R2 are The 2′-deoxyguanosine derivative according to [1], which is a phenyl group substituted at least at the 4-position, and a salt thereof, [3] a general formula [2]
[Formula 12]

[0008]

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(Wherein R1 and R2 each independently represent a phenyl group which may be substituted, and X represents a halogen atom); and a compound represented by the general formula: [3] [Formula 13]

[0010]

[Formula 13]

(Wherein R3 represents a phenyl group which may be substituted). A method for producing the 2′-deoxyguanosine derivative and the salt thereof according to [1], by reacting the derivative with a guanine derivative represented by the formula: [4] The method for producing a 2′-deoxyguanosine derivative and a salt thereof according to [3], wherein the guanine derivative is formed into a metal salt or an amine salt, and the reaction is carried out in an aprotic solvent.
[5] General formula [1]

[0012]

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(Wherein R1, R2 and R3 have the same meanings as [1]) by removing the protecting group of the compound represented by the formula [4].

[0014]

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(Wherein R1 and R2 have the same meanings as described above), and a method for producing 2′-deoxyguanosine and a salt thereof represented by the following general formula [6]:
6]

[0016]

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(Wherein, R1 and R2 each independently represent a phenyl group which may be substituted.
Excluding the case where both are unsubstituted phenyl groups) 2'-deoxyguanosine derivatives and salts thereof,
[7] The 2'-deoxyguanosine derivative according to [6], wherein R1 and R2 are phenyl groups substituted at least at the 4-position, and a salt thereof, [8] a general formula [1]

[0018]

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(Wherein R1, R2 and R3 have the same meanings as [1]) by removing the benzyl group of the compound represented by the general formula [5]

[0020]

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(Wherein R1 and R2 have the same meanings as [5]), and a method for producing a 2′-deoxyguanosine derivative and a salt thereof, [9] a general formula [5]
[Formula 19]

[0022]

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(Wherein R1 and R2 have the same meanings as [5]) by removing the acyl-protecting group of the compound represented by the formula (4).

[0024]

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This is a method for producing 2'-deoxyguanosine and a salt thereof shown in the above.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The phenyl group of R1 and R2 in the 2′-deoxyguanosine derivative represented by the general formula [1] may be an unsubstituted phenyl group or may be located at any of the 2-, 3-, and 4-positions on the phenyl group. There may be substituents. Further, a substituent may be present at a plurality of positions. Examples of the substituent include an alkyl group such as a methyl group, an ethyl group, a propyl group, a 2-propyl group, a butyl group and a t-butyl group, a hydroxyl group, a methoxy group, an ethoxy group and an alkyloxy group such as a propyloxy group; Group, chloro group, bromo group, halogeno group such as iodine group, acyl group such as acetyl group, propionyl group, alkylamino group such as methylamino group, ethylamino group, propylamino group, dimethylamino group, unsubstituted amino Group, nitro group, cyano group and the like.

Specifically, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl,
4-methoxyphenyl group, 3-methoxyphenyl group, 2
-Methoxyphenyl group, 4-chlorophenyl group, 3-chlorophenyl group, 2-chlorophenyl group, 4-bromophenyl group, 3-bromophenyl group, 2-bromophenyl group, 4-acetylphenyl group, 3-acetylphenyl group, 2-acetylphenyl group, 4-nitrophenyl group,
Examples thereof include a 3-nitrophenyl group, a 2-nitrophenyl group, a 4-cyanophenyl group, a 3-cyanophenyl group, and a 2-cyanophenyl group. Preferably a 4-methylphenyl group, a 4-chlorophenyl group, a 4-bromophenyl group,
A 4-nitrophenyl group and a 4-cyanophenyl group.

The phenyl group for R3 may be an unsubstituted phenyl group or a substituent at any of the 2-, 3- and 4-positions on the phenyl group. Further, a substituent may be present at a plurality of positions. Examples of the substituent include a methyl group, an ethyl group, a propyl group, a 2-propyl group, a butyl group, a t-
Alkyl groups such as butyl group, alkyloxy groups such as hydroxyl group, methoxy group, ethoxy group and propyloxy group; halogen groups such as fluoro group, chloro group, bromo group and iodo group; acyl groups such as acetyl group and propionyl group And alkylamino groups such as methylamino group, ethylamino group, propylamino group and dimethylamino group, unsubstituted amino group, nitro group and cyano group. The number of substituents may be one or more, and there may be no substituent.

Specifically, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl,
4-methoxyphenyl group, 3-methoxyphenyl group, 2
-Methoxyphenyl group, 4-acetylphenyl group, 3-
Examples include an acetylphenyl group, a 2-acetylphenyl group, a 4-nitrophenyl group, a 3-nitrophenyl group, a 2-nitrophenyl group, a 4-cyanophenyl group, a 3-cyanophenyl group, a 2-cyanophenyl group, and the like.

In the compound represented by the general formula [2], R
1 and R2 are the same as R1 and R2 in the general formula [1].

X represents a halogeno group. Specific examples include a fluoro group, a chloro group, a bromo group, an iodo group and the like, and preferred are a chloro group and a bromo group.

In the compound represented by the general formula [3], R
3 is the same as R3 in the general formula [1].

The compound of the general formula [1], which is the target compound of the present invention, can be obtained by converting the compound of the general formula [3] into a salt and reacting it with the compound of the general formula [2]. Can be. The compound represented by the general formula [2] can be obtained by the method described in JP-A-7-224081. The compound represented by the general formula [3] is, for example,
It can be obtained by the method described in JP-A-10-218880. Salts of the compound represented by the general formula [3] include inorganic salts such as lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, magnesium salt, calcium salt and the like, ammonium salt, triethylammonium salt, tetraethylammonium salt, tetraethylammonium salt and the like. Ammonium salts such as butyl ammonium salt and benzyl trimethyl ammonium salt can be used.

For example, the following method is used as a salt-forming operation. The compound represented by the general formula [3] is dissolved or suspended in a solvent, and sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium methoxide, potassium methoxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide and the like are dissolved therein. And the mixture is stirred, and the solvent is distilled off under reduced pressure and dried.

Examples of the solvent used for salt formation include water, methanol, ethanol, propanol, 2-propanol, acetonitrile, dioxane, THF and the like. The salt forming temperature can be any temperature, but is preferably
0 ° C to 150 ° C.

The reaction between the compound represented by the general formula [2] and the salt of the compound represented by the general formula [3] is performed in an aprotic solvent. Examples of aprotic solvents include acetone, 2-butanone, DMF, DMI, N-methylpyrrolidone, benzene, toluene, orthodichlorobenzene, chloroform, dichloromethane, THF, dioxane, ethylene glycol dimethyl ether, pyridine,
Ethyl acetate, butyl acetate, acetonitrile and the like are used, preferably acetone, 2-butanone, DMF, DM
I, acetonitrile.

The amount of the solvent used is 3 to 100 times, preferably 10 to 50 times the amount of the compound represented by the general formula [2]. The reaction temperature is from -30 ° C to 150 ° C, preferably from 0 ° C to 50 ° C. Reaction time from 15 minutes to 24
Time.

The compound represented by the general formula [1] is obtained by removing the protecting group from the compound represented by the general formula [4].
Deoxyguanosine can be produced. The elimination reaction of the protecting group may be carried out in the order of a benzyl group and an acyl group, or vice versa. Also, they may go at once. Intermediates may or may not be isolated.

In the compound represented by the general formula [5], which is an intermediate when the compound represented by the general formula [4] is produced from the compound represented by the general formula [1], R1 and R2 are represented by the general formula [1] Are the same as R1 and R2. This compound has increased crystallinity because the 3′- and 5′-positions of the sugar moiety are protected by a benzoyl group, particularly a 4-substituted benzoyl group.
It is characterized by being easy to handle for purification and the like.

The compound represented by the general formula [5] can be produced by removing the benzyl group of the compound represented by the general formula [1]. Examples of the desorption method include hydrogenolysis, but the method is not limited to this method. Examples of the solvent used for hydrogenolysis include methanol, ethanol, 2-propanol, dioxane, THF, ethyl acetate and the like, and a mixed solvent thereof.

As the catalyst, any catalyst used for ordinary hydrogenolysis, such as palladium, platinum, platinum oxide, ruthenium, etc., or those holding these on a carrier can be used.
The hydrogen pressure can be from normal pressure to 10 MPa, but is preferably from normal pressure to 1 MPa. The reaction temperature is from 0 ° C to 150 ° C, preferably from 10 ° C to 50 ° C. The reaction time varies depending on the stirring efficiency, but is usually 30 minutes to 48 hours.

The compound represented by the general formula [5] can be converted to 2'-deoxyguanosine by deprotecting the benzoyl protecting group. 2'-Deoxyguanosine can be obtained by reacting with water, methanol, ethanol, dioxane, THF or the like as a solvent and a base such as sodium hydroxide, potassium hydroxide, sodium methoxide or ammonia.

2'-deoxyguanosine has the general formula [1]
Can be obtained by first deprotecting the acyl group of the compound represented by and then removing the benzyl group.

The 2'-deoxyguanosine obtained according to the present invention can be used as it is, but can be purified by a commonly used method such as a recrystallization method to obtain higher purity 2'-deoxyguanosine.
-Deoxyguanosine can be obtained. Further, this can be further converted to a commonly used salt for use.

As described above, according to the present invention, 2′-deoxyguanosine can be produced more efficiently.

[0046]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 Methanol was added to 8.4 g of 2-amino-6-O-benzylpurine.
126 mL was added, and the mixture was dissolved by heating under reflux. Here, a solution obtained by mixing 1.88 g of sodium methoxide and 15 mL of methanol was added.
It was added dropwise over 0 minutes. After the completion of the dropwise addition, the mixture was heated under reflux for 1 hour. After cooling to room temperature, the solvent was distilled off under reduced pressure. Toluene 50m
L was added and the solvent was distilled off under reduced pressure. This operation was repeated three times. 252 mL of acetonitrile was added to the residue, and the mixture was stirred at room temperature. 12.5 g of 85% pure 3,5-di (4-chlorobenzoyl) -1-chloro-2-deoxyribose was added to 1
Charged separately in 0 times. After charging the whole amount, the mixture was stirred at room temperature for 2 hours, and insoluble materials were removed by filtration. The filtrate was concentrated to dryness, and the residue was purified by column chromatography on silica gel. 8.44 g of 2-amino-6-O-benzyl-9- {3,5-bis (4-chlorobenzoyl) -2′-deoxy-β-D-ribofuranosyl} -purine was obtained. The total yield of α-form and β-form was 53.8%, and the ratio of β-form / α-form was 90/10. Melting point: 200 ° C (decomposition) ¹ H-NMR (270 MHz, DMSO-d6): 2.70-
2.76 (m, 1H), 3.19-3.29 (m, 1H), 4.54-4.57 (m, 2H), 4.64
-4.72 (m, 1H), 5.50 (s, 2H), 5.76 to 5.78 (m, 1H), 6.39 (t,
1H), 6.56 (brs, 2H), 7.35-7.66 (m, 13H), 7.95-8.10 (m,
9H) IR (cm ^-1 ): 1722, 1613, 1582, 1458, 1403, 126
7, 1092, 1014, 759 MS: 634 (MH ⁺ ) Example 2 To 24.1 g of 2-amino-6-O-benzylpurine was added 500 mL of methanol and dissolved by heating under reflux. 6.6 g of potassium hydroxide (purity 85%) was added thereto, and the mixture was heated under reflux for 1 hour.
After cooling to room temperature, the solvent was distilled off under reduced pressure. Toluene 50
mL was added and the solvent was distilled off under reduced pressure. This operation was repeated three times. The residue was dried to obtain 29 g of a potassium salt. 750 mL of acetonitrile was added to 24 g of the potassium salt, and the mixture was stirred at room temperature. Here, 29 g of 3,5-di (4-chlorobenzoyl) -1-chloro-2-deoxyribose having a purity of 85% was divided and charged in 90 minutes in 10 divided portions. After charging the whole amount, the mixture was stirred at room temperature for 2 hours, and insoluble materials were removed by filtration. The filtrate was concentrated to dryness, and the residue was purified by column chromatography on silica gel. 2-
Amino-6-O-benzyl-9- {3,5-bis (4-
16.56 g of (chlorobenzoyl) -2′-deoxy-β-D-ribofuranosyl} -purine were obtained. The total yield of α-form and β-form was 45.5%, and the ratio of β-form / α-form was 92/8. Example 3 2-amino-6-O-benzyl-9- {3,5-bis (4-chlorobenzoyl) -2′-deoxy-β-D-
8.0 g of ribofuranosyl II-purine was dissolved in a mixed solvent of 160 mL of ethyl acetate and 80 mL of ethanol. 50% we here
0.8 g of t10% Pd / C (10% Pd supported on activated carbon and 50% water content) was added. The system was replaced with hydrogen, and the mixture was stirred at a hydrogen pressure of 0.5 MPa and 50 ° C. for 7 hours. After sufficiently replacing the inside of the system with nitrogen, 160 mL of THF was added. The catalyst was removed by filtration and washed three times with 20 mL of THF. The filtrate was combined, the solvent was distilled off, and the residue was sludged by adding 8 mL of methanol. The crystals were collected by filtration and washed with 1 mL of methanol. The crystals were dried under reduced pressure to obtain 3.62 g of 9- {3,5-bis (4-chlorobenzoyl) -2′-deoxy-β-D-ribofuranosyl} -guanosine. The total yield of α-form and β-form was 52.7%. Melting point: 149 ° C. ¹ H-NMR (270 MHz, DMSO-d6): 2.68-
2.75 (m, 1H), 3.11-3.19 (m, 1H), 4.54-4.66 (m, 3H), 5.74
-5.75 (m, 1H), 6.30 (t, 1H), 6.54 (brs, 2H), 7.52-7.66
(m, 8H), 7.92-8.05 (m, 9H), 10.74 (s, 1H) IR (cm ^-1 ): 1719, 1630, 1536, 1488, 1402, 127
4, 1173, 1093, 1015, 760 MS: 544 (MH ^<+> ) Example 4 9- {3,5-bis (4-chlorobenzoyl) -2'-
Deoxy-β-D-ribofuranosyl｝ -guanosine 3.4 g
Was suspended in 102 mL of methanol and cooled to 6 ° C. Ammonia gas (13.6 g) was blown under ice cooling, and after the blowing was completed, the solution was left overnight at room temperature. The reaction solution was concentrated to dryness, and sludge was added with 68 mL of ethyl acetate. The crystals were filtered and washed with 3 mL of ethyl acetate. The obtained crystals were dried to obtain 1.5 g of 2'-deoxyguanosine monohydrate. Total yield of α-form and β-form 90
%. β / α ratio 94/6. The recrystallization was repeated three times with water to which a very small amount of aqueous ammonia was added to obtain 2'-deoxyguanosine monohydrate. The total yield of α-form and β-form from 9- {3,5-bis (4-chlorobenzoyl) -2′-deoxy-β-D-ribofuranosyl} -guanosine is 40.
%, The β-form / α-form ratio was 99.5 / 0.5, and the guanine content was 0.7%. Melting point:> 240 ° C ¹ H-NMR (270 MHz, DMSO-d6): 2.15-
2.23 (m, 1H), 2.45-2.54 (m, 1H), 3.34-3.53 (m, 2H), 3.80
-3.81 (m, 1H), 4.33 (m, 1H), 4.96 (brs, 1H), 5.26 (brs, 1
H), 6.12 (dd, 1H, J = 6.3Hz, 7.9Hz), 6.48 (brs, 2H), 7.91
(s, 1H), 9.73 (brs, 1H) IR (cm ^-1 ): 3324, 1690, 1656, 1612, 1584, 153
5,1485,1056 MS: 268 (MH ^<+> ) Example 5 2-Amino-6-O-benzyl-9- {3,5-bis (4-chlorobenzoyl) -2'-deoxy- [beta] -D-.
To 2.2 g of ribofuranosyl II-purine, 33 mL of 14% methanolic ammonia was added, and the mixture was stirred at room temperature for 8 hours. The reaction solution was concentrated to dryness, and toluene was added to the residue to sludge. The supernatant was decanted and toluene was added to the residue. Decanting was performed again and the residue was dried. 6-O-benzyl-
1.19 g of 2'-deoxyguanosine was obtained. The total yield of α-form and β-form was 96%.

30 mL of ethanol and 30 mL of water were added to 1.0 g of 6-O-benzyl-2'-deoxyguanosine. Here 5
0.20 g of 0% wet, 10% Pd / C (10% Pd supported on activated carbon and 50% water content) was added, and the system was replaced with hydrogen. The mixture was stirred at a hydrogen pressure of 0.5 MPa and room temperature for 5 hours. The system is sufficiently purged with nitrogen, the catalyst is removed by filtration, and ethanol is removed.
Washed with 5 mL. The filtrate was concentrated under reduced pressure to 15.5 g and crystallized. The precipitated crystals were collected by filtration and washed with water. 0.53 g of 2'-deoxyguanosine monohydrate was obtained. α-isomer and β-isomer
66% total body yield. β-form / α-form ratio of 97.8 / 2.2.
This was repeated twice with water to which a very small amount of aqueous ammonia was added to obtain 2'-deoxyguanosine monohydrate. 6
The total yield of α-form and β-form from —O-benzyl-2′-deoxyguanosine is 43%, and the ratio of β-form / α-form is 99.6.
/0.4.

[0048]

Industrial Applicability According to the present invention, 2'-deoxyguanosine can be produced more efficiently and in a higher yield than a conventional method by using a method capable of mass production.

Claims (9)

[Claims] [Claim 1] A compound represented by the general formula [1] (In the formula, R1, R2, and R3 each independently represent a phenyl group which may be substituted.) 2'-deoxyguanosine derivatives and salts thereof. 2. The 2′-deoxyguanosine derivative and the salt thereof according to claim 1, wherein R1 and R2 are phenyl groups substituted at least at the 4-position. 3. A compound of the general formula [2] (Wherein, R1 and R2 each independently represent a phenyl group which may be substituted, and X represents a halogen atom), and 1-α-halogeno-2-deoxyribofuranose represented by the general formula [3]: [Formula 3] [Formula 3] (Wherein, R3 represents a phenyl group which may be substituted). The method for producing a 2′-deoxyguanosine derivative and a salt thereof according to claim 1, by reacting a guanine derivative represented by the following formula: 4. The method for producing a 2′-deoxyguanosine derivative and a salt thereof according to claim 3, wherein the guanine derivative is formed into a metal salt or an amine salt, and the reaction is carried out in an aprotic solvent. 5. A compound of the general formula [1] (In the formula, R1, R2, and R3 have the same meaning as in claim 1.)
By removing the protecting group of the compound represented by the formula [4], (Wherein, R 1 and R 2 have the same meanings as described above.) 2'-deoxyguanosine and a salt thereof. 6. A compound of the general formula [5] (Wherein, R1 and R2 each independently represent a phenyl group which may be substituted, provided that R1 and R2 are each an unsubstituted phenyl group), and a 2′-deoxyguanosine derivative represented by the formula: . 7. The 2′-deoxyguanosine derivative and salt thereof according to claim 6, wherein R1 and R2 are phenyl groups substituted at least at the 4-position. 8. A compound of the general formula [1] (In the formula, R1, R2, and R3 have the same meaning as in claim 1.)
By removing the benzyl group of the compound represented by the general formula [5] [formula 8] (Wherein, R1 and R2 have the same meanings as in claim 5). A method for producing a 2′-deoxyguanosine derivative represented by the formula: 9. A compound of the general formula [5] (Wherein R1 and R2 have the same meanings as in claim 5) by removing the acyl-protecting group of the compound represented by the formula [4]. A method for producing 2′-deoxyguanosine and a salt thereof represented by the formula: