JPH07258178A - Production of natural sphingosines and synthetic intermediate thereof - Google Patents

Abstract

PURPOSE:To obtain the compound from inexpensively and readily obtainable starting raw materials by reacting N-benzoyl-D-glucosamine with an acetalizing agent, then reducing, sulfonylating, deacetalizing, iodizing and treating with a base. CONSTITUTION:N-Benzoyl-D-glucosamine is reacted with an acetalizing agent to give a 4,6-acetal of the formula I (Bz is benzoyl R<4> is a 1-4C alkyl or phenyl; R<6> is H, a 1-4C alkyl, etc.). The compound is reduced to obtain a 2-benzamido-2- deoxy-D-glucitol derivative. The derivative is simultaneously sulfonylated and made into an oxanoline derivative to obtain a phenyloxazoline derivative of the formula II (Ph is phenyl; R is a 1-4C acetal or an aryl), which is acetalized, the iodized and simultaneously eliminated reductively to give an end vinyl compound of the formula III. The compound is treated with a base, the prepared epoxide is reacted with a dodecyl Grignard reagent in the presence of a curpous salt, the oxanoline ring is cleft and the benzonyl group is eliminated to obtain the compound of the formula IV (R<1> to R<3> each is H).

Description

Detailed Description of the Invention

[0001]

The present invention relates to a natural sphingosine {(2S, 3R, 4 represented by the following general formula (1).
E) -2-Amino-1,3-dihydroxy-4-octadecene (R ¹ , R ² and R ³ in the formula are hydrogen)} and acyl derivatives thereof, and a synthetic intermediate thereof. More specifically, it is a common structural skeleton of glycosphingolipids and sphingophospholipids, which are membrane constituents of animal cells and some plant cells and are considered to be involved in various recognition actions in the cell surface. The present invention relates to a method for efficiently producing the compound (sphingosine) and a synthetic intermediate in the production method.

[0002]

2. Description of the Related Art In recent years, research in the fields of medicine and biochemistry has revealed the importance of glycosphingolipids in vivo. In other words, it is suggested that they play important roles in mutual recognition between cells, regulation of cell growth, regulation of development / differentiation, infection and malignant transformation of cells, and also receptor function of toxins, antiulcer property, antiviral property. , Glycosphingolipids having physiological and pharmacological activities such as neurite extension promotion have been discovered one after another (Scientific American (Scient
ific American) Vol. 254, p. 44 (1986)). It was also found that these long-chain base sphingosine, which is a common skeleton of the hydrophobic part, itself has an activity-regulating activity of protein kinase C, which is an enzyme essential for intracellular signal transduction (Science (Sci
ence) Volume 243, page 500 (1989)). It is also known that ceramide, which is an N-long chain acyl derivative of sphingosine, has a moisturizing action on the stratum corneum of the skin. As mentioned above, sphingosines are substances with very interesting properties, but since they exist as a complex mixture in biological membranes, it is difficult to extract pure lipids with a single structure from natural sources in large amounts. is there. Therefore, in order to obtain a large amount of chemically pure lipids, the most abundant basic structure D
-A chemical synthesis method of erythro- _C18 -sphingosine has been studied, and more than 20 cases have been reported so far. However, since sphingosine has two asymmetric carbons and one double bond, it is not yet easy to chemically synthesize one having the same configuration as the natural type. For example, a method that requires 10 or more steps from a starting material (Journal of Organic Chemistry, Vol. 35, page 4127 (1970).
)) Or as a mixture with non-natural isomers (Journal of Organic Chemistry (J. Org. Chem.) No. 46)
Volume, 4393 pages (1981)). Among them, a method of obtaining D-galactose as a starting material in 7 steps and a total yield of about 25% (Tetrahedron Lett., Vol. 27, 4)
81 (1986)), a method of obtaining L-serine as a raw material in 6 steps and a total yield of about 35% (Journal of Organic Chemistry), Vol. 53, p. 4395 (1988). )) And L-valine as raw materials in 7 steps with a total yield of about 30% (Journal of the American Chemical Society (J. Am. Chem.
Soc.) 110, 7910 (1988)) is known to be relatively efficient. However, the reagents used in the intermediate steps are expensive, and need to be prepared separately.
Alternatively, there are still points to be improved for industrial production, such as requiring complicated operations.

[0003]

The object of the present invention is to be carried out industrially so that the desired product can be produced in a short process in a good yield using inexpensive and easily available starting materials and reaction reagents in the intermediate step. Another object of the present invention is to provide a method for producing a natural sphingosine which is advantageous for the production of sphingocin and a synthetic intermediate useful for the production.

[0004]

Means for Solving the Problems As a result of intensive studies by the present inventors, a novel efficient synthetic route starting from N-benzoyl-D-glucosamine and its synthetic intermediate can be suitable for the purpose. It was found that the present invention has been completed.

That is, according to the present invention, N-benzoyl-D-glucosamine is used as a starting material, and the following general formula (1) is used.

[0006]

[Chemical 16]

In the method for producing a natural sphingosine represented by the formula (wherein R ₁ , R ² and R ³ represent hydrogen atoms), (i) N-benzoyl-D-glucosamine is reacted with an acetalizing agent. General formula (2)

[0008]

[Chemical 17]

(In the formula, Bz is a benzoyl group, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms or an optionally substituted phenyl group, and R ⁶ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Or R ⁴ and R ⁶ each represent a methylene group having 4 to 7 carbon atoms bonded to its terminals) 4,6
-First step of obtaining acetal, (ii) reduction of 4,6-acetal obtained in the first step to give the following general formula (3)

[0010]

[Chemical 18]

The second step of obtaining a 2-benzamido-2-deoxy-D-glucitol derivative represented by the formula (wherein Ph, R ⁴ and R ⁶ have the same meanings as described above), (iii) the second step The 2-benzamido-2-deoxy-D-glucitol derivative obtained in the step is sulfonylated and oxazolineized at the same time to give the following general formula (4):

[0012]

[Chemical 19]

(In the formula, Ph is a phenyl group, R is a carbon number 1
~ 4 is an alkyl group or an optionally substituted aryl group, and R ⁴ and R ⁶ have the same meanings as described above), the third step of obtaining a phenyloxazoline derivative, (i
v) Deacetalization of the faenyloxazoline derivative obtained in the third step, to give a compound represented by the following general formula (5)

[0014]

[Chemical 20]

A fourth step of obtaining a diol compound represented by the formula (wherein Ph and R have the same meaning as described above),
(V) The diol compound obtained in the fourth step is iodinated and simultaneously reductively eliminated to give a compound represented by the following general formula (6):

[0016]

[Chemical 21]

A fifth step of obtaining a terminal vinyl compound represented by the formula (wherein Ph and R have the same meaning as described above),
(Vi) The vinyl compound obtained in the fifth step is treated with a base to give the following general formula (7):

[0018]

[Chemical formula 22]

(Wherein Ph has the same meaning as above)
A sixth step of obtaining an epoxide represented by the formula (vii): the epoxide obtained in the sixth step is reacted with a dodecyl Grignard reagent in the presence of a monovalent copper salt to give a compound represented by the following general formula (8):

[0020]

[Chemical formula 23]

(Wherein Ph has the same meaning as above)
A seventh step for obtaining a dodecyl group-containing compound represented by
ii) The dodecyl group-containing compound obtained in the seventh step is cleaved at its oxazoline ring under acidic conditions, and its benzoyl group is eliminated to give the natural sphingosine represented by the general formula (1). An eighth step of obtaining the natural sphingosine is provided.

According to the present invention, the general formula (7)
There is provided a method for producing a dodecyl group-containing compound represented by the general formula (8), which comprises reacting an epoxide represented by the formula (9) with a dodecyl Grignard reagent in the presence of a monovalent copper salt.

Furthermore, a 2-benzamido-2-deoxy-D-glucitol derivative represented by the above general formula (3) is provided.

Furthermore, a phenyloxazoline derivative represented by the above general formula (4) is provided.

Furthermore, the diol compound represented by the above general formula (5) is provided.

Furthermore, a terminal vinyl compound represented by the above general formula (6) is provided.

Furthermore, the epoxide represented by the general formula (7) is provided.

Natural sphingosines can be produced by sequentially performing the reactions in the following steps. N-benzoyl-D represented by the following formula (9) as a starting material
-Glucosamine can be easily synthesized from D-glucosamine hydrochloride, which is inexpensive and available in large quantities as a chitosan hydrolyzate, and a benzoylating agent such as benzoyl chloride (Journal of the American Chemical Chemicals). Society (J. Am. Chem.
Soc.) Vol. 78, p. 4722 (1956)), or commercially available products can also be used.

[0029]

[Chemical formula 24]

(Step 1) In this step, the hydroxyl groups at the 4-position and the 6-position of N-benzoylglucosamine are reacted with an acetalizing agent by a known method to give 4,6-, represented by the general formula (2). This is a step of obtaining O-acetal. Two methods of acetalization are roughly known here. The first method is a method of reacting a raw material compound (9) represented by the formula (9) with an aldehyde in the presence of an acid catalyst (Acta. Chem. Scand.) Volume 24, 173 pages (1970
In the case of an aliphatic aldehyde, it is preferable to carry out the reaction in acetonitrile with concentrated hydrochloric acid or concentrated sulfuric acid as a catalyst, and in the case of an aromatic aldehyde, it is preferable to carry out the reaction with no solvent or dioxane using zinc chloride as a catalyst. The second method is a raw material compound (9) represented by the formula (9) and a dialkyl acetal derivative of an aldehyde or a ketone (1-2 equivalents).
In the presence of an acid catalyst in a solvent, particularly preferably N, N-dimethylformamide (DMF), for acetal exchange (Carbohydr. Res.) Vol. 29, 209
Page (1973)). By this method, an isopropylidene compound (R ⁴ and R ⁶ in the formula are methyl groups) and a benzylidene compound (R ⁴ in the formula is a phenyl group and R ⁶ is a hydrogen atom) of the compound (2) represented by the general formula (2). Atom), a cyclohexylidene body (R ^{4 to} R ⁶ in the formula are methylene chains having 5 carbon atoms) and the like can be obtained. However, the yield of this method is about 70 to 80%, and there are problems that a step of separating unreacted raw materials is required after the reaction and that DMF having a relatively high boiling point needs to be distilled off. As an improved method of the first method, a method of reacting compound (9) with a large excess of paraaldehyde (a cyclic trimer of acetaldehyde) at room temperature in the presence of an acid catalyst, particularly preferably concentrated sulfuric acid (tetrahedron (Tetrahedron) 44
Vol., P. 7177 (1988)), and an ethylidene acetal compound (2) (in the formula, R ⁴ is a methyl group and R ⁶ is a hydrogen atom) is obtained. This method is extremely simple because it can be used for the reaction in the next step simply by filtering and washing the crystals formed during the reaction.

(Step 2) The hemiacetal aldehyde at the C-1 position of the compound (2) is reduced to give the compound of the general formula (3)
Is a step of obtaining a 2-benzamido-2-deoxy-D-glucitol derivative represented by. The reaction can be carried out in a solvent in the presence of a reducing agent. As the reducing agent, an alkali metal borohydride such as sodium borohydride or lithium borohydride is suitable. Water as solvent,
Protic solvents such as methanol, ethanol and propanol, ethers such as tetrahydrofuran and dioxane, or mixed solvents thereof are used. Reaction is -20 ℃
To room temperature. In particular, 2-propanol / water = 6: 1
When 1 to 2 equivalents of sodium borohydride was used in the mixed solvent, the reaction was completed at 0 ° C. in about 1 hour to give compound (3).
It is obtained in a high yield of 90% or more.

(Step 3) C-1,3 of the compound (3)
In this step, the hydroxyl group at the 5-position is sulfonylated to give a phenyloxazoline derivative represented by the general formula (4). As the sulfonylating agent, methanesulfonyl chloride, p-toluenesulfonyl chloride and the like are preferable. As the base, tertiary amines such as triethylamine and pyridine are preferable. Most preferably, the solvent is a halogen-based solvent such as methylene chloride or chloroform. With the combination of methanesulfonyl chloride and triethylamine the sulphonylation is complete within 30 minutes below 0 ° C. Furthermore, when this reaction solution is stirred at room temperature for several hours, the sulfonyloxy group at the C-1 position is eliminated and 2-
A phenyloxazoline ring is formed, and compound (4) (R in the formula is a methyl group) is obtained in a yield of 90% or more.

(Step 4) In this step, the acetal-protecting group of the compound (4) is removed to obtain the diol compound represented by the general formula (5). The reaction is carried out by using an acid catalyst and thiol in a solvent. Titanium tetrachloride as an acid,
Lewis acids such as boron trifluoride diethyl ether complex are preferred. As thiol, aliphatic thiol such as ethanethiol and ethylenedithiol, aromatic thiol such as thiophenol and the like can be used. Reaction is -20 ℃
Although it can be carried out at room temperature, the reaction proceeds smoothly at around 0 ° C., and the reaction time of about 2 hours is sufficient. In the case of ethylidene acetal, the use of titanium tetrachloride gives better results. Other acetals can be removed with a boron trifluoride ether complex under cooling. On the other hand, if the acid hydrolysis is carried out in this step, the oxazoline ring is cleaved and the purpose cannot be achieved.

(Step 5) In this step, the compound (5) is reacted with an iodizing agent to obtain a terminal vinyl compound represented by the general formula (6). Iodine is suitable as the iodination agent. As the solvent, hydrocarbon solvents such as benzene and toluene, and halogen solvents such as methylene chloride and dichloroethane are preferable. Triphenylphosphine,
An organic phosphorus agent such as tributylphosphine and triphenyl phosphite and an amine base such as pyridine and imidazole are required. The reaction temperature is preferably 0 to 80 ° C., particularly 60 to 70 ° C., and the reaction time when heating is 1 hour. According to this method, the target compound (6) has a yield of 60-
Obtained at 70%.

(Step 6) This step is a step of treating the compound (6) with a base to obtain an epoxide represented by the formula (7). As the base, an alkali metal hydroxide, carbonate, alkoxide, hydride or the like can be used. As the solvent, depending on the nature of the base used, water, a protic solvent such as methanol or ethanol, an ether such as tetrahydrofuran or dioxane, a halogen system such as methylene chloride, DMF, or a mixed solvent thereof can be used. . A simple method is to carry out the reaction at 0 ° C. to room temperature in methanol using alkali metal carbonate as a base.
The compound (7) is obtained with a yield of about 90%.

(Seventh Step) In this step, a dodecyl group is introduced at the C-6 position of the compound (7) to obtain the compound represented by the formula (8). The reaction is carried out in a solvent using a Grignard reagent and a monovalent copper salt. As the solvent, ether solvents such as ether, tetrahydrofuran and dimethoxyethane are preferable. Grignard reagent (dodecylmagnesium bromide)
Can be a commercially available product (1 molar ether solution), or can be easily prepared from dodecyl bromide and magnesium in an ether solvent. As the monovalent copper salt, cuprous halide, cuprous cyanide and the like can be used, and the amount is 0.02 to 0.5 equivalent of the compound (7) is sufficient. The reaction is preferably carried out at -80 to -20 ° C, especially at -70 to -50 ° C. As a result, the compound (8) having the same configuration as natural sphingosine is selectively obtained with a yield of 90% or more. The total yield from the starting material / compound (9) to the compound (8) obtained in this step is 30 to 40%. This compound (8) is a compound in which the 1-position hydroxyl group and the 2-position amino group of sphingosine are protected, and is a compound known in the literature (Journal of Organic Chemistry (J. Org. Chem.) Vol. 46, 43
Page 93 (1981)).

(Step 8) Compound (8) is deprotected to give natural sphingosine (R ¹ in the general formula (1),
R ² and R ³ are hydrogen atoms). General formula (8)
The oxazoline ring of the compound represented by can be cleaved by acidic hydrolysis. The reaction can be performed using hydrochloric acid, sulfuric acid, p-toluenesulfonic acid or the like as a catalyst, while mixing water and an organic solvent, at room temperature or under heating for several tens of minutes to twenty and several hours. The thus-obtained hydrochloride of 1-O-benzoylsphingosine (the general formula (1), in which R ¹ is a benzoyl group, R ² and R ³ are hydrogen atoms) is a known substance,
Known method (Journal Off Organic Chemistry (J. Org. Che
m.) Vol. 46, p. 4393 (1981)), with 12 to 12 carbon atoms.
A linear acylating agent which may have 18 double bonds is reacted to give ceramide (R ¹ and R ³ in the general formula (1) are hydrogen atoms, and R ² is a diamine having 12 to 18 carbon atoms. It can be easily converted into a linear acyl group which may have a heavy bond). That is, various amides are obtained by reacting 1-O-benzoylsphingosine with an active acylating agent under weakly basic conditions, and by removing the benzoyl group, ceramide (R ¹ in the general formula (1) is , R ³ is a hydrogen atom, R ² is a linear acyl group having 12 to 18 carbon atoms and optionally having a double bond)
Can be obtained. When alkali hydroxide acts on the 1-O-benzoylsphingosine, the benzoyl group is rearranged to become N-benzoylsphingosine (R ¹ and R ³ in the general formula (1) are hydrogen atoms, and R ² is a benzoyl group), The basic aqueous solution (about 1N concentration) is heated for a long time (95 ° C,
12 hours or more), the natural type D-erythro-C ₁₈
-Sphingosine (R ¹ , R ² , and R ³ in the general formula (1) are hydrogen atoms) can be obtained. On the other hand, a protecting group that is basic and easily hydrolyzed to the amino group of 1-O-benzoylsphingosine, for example, an acyl group such as trifluoroacetyl group or trichloroacetyl group, or an ethoxycarbonyl group or a benzyloxycarbonyl group. When such a carbonate group is introduced, hydrolysis is completed in a short time (within 3 hours, 90 ° C.), and sphingosine can be obtained. In this way, 8 steps from the starting material / compound (9), total yield 25
The natural sphingosine obtained in an amount of ˜30% can be triacetylated by a known method to confirm the structure (R ¹ , R ² and R ³ in the general formula (1) are acetyl groups).

Compound (3), compound (4), compound (5), compound (6), which is a synthetic intermediate in the present invention,
The compound (7) is a novel compound not yet published in the literature, and its structure was identified and confirmed by various spectrum analyzes and elemental analyses. Further, the compound (1), the compound (2), the compound (3), and the compound (8) are known substances described in the literature except for some of them, and the physical properties thereof are almost the same as the literature values.

[0039]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Reference Examples. Example 1 (Step 1) 4.0 g (14.1 mmol) of N-benzoyl-D-glucosamine (compound (9)) was suspended in 40 ml of paraaldehyde, and 0.1 ml (1.8 mmol) of concentrated sulfuric acid was added while cooling with ice. In addition, the mixture was stirred at room temperature for 20 hours. After 1 ml of triethylamine was added for neutralization, 40 ml of ether was added for dilution, and the resulting white solid was collected by filtration. After thoroughly washing with ether and drying under reduced pressure, 4,6-O-ethylidene-N-benzoyl-D was obtained.
-Glucosamine (compound (2), in which R ⁴ is a methyl group and R ⁶ is a hydrogen atom) was obtained in an amount of 4.10 g (yield 94%). Melting point 225 to 228 ° C Rf value 0.50 (AcOEt) ¹ H-NMR (CDCl ₃ / CD ₃ OD) (mainly α-anomer) δ 1.39
(3H, d, J = 5.0 Hz), 3.40 (1H, t, J = 9.5 Hz), 3.57 (1
H, t, J = 10.2 Hz), 3.95 (1H, dt, J = 4.8, 9.5 Hz), 3.
97 (1H, t, J = 9.8 Hz), 4.09 (1H, dd, J = 4.8, 9.5 H
z), 4.22 (1H, dd, J = 3.7, 10.1 Hz), 4.80 (1H, q, J =
5.0 Hz), 5.25 (1H, d, J = 3.6 Hz), 7.30 (1H, d, J = 8.
4 Hz), 7.44 (2H, m), 7.51 (1H, m), 7.83 (2H, m).

(Second step) 4,6-O-ethylidene-N
-Benzoyl-D-glucosamine 930 mg (3.0 mmol) 2
-Dissolved in 24 ml of propanol and 4 ml of water, 180 mg (4.7 mmol) of sodium borohydride was added little by little while cooling with ice, and the mixture was further stirred for 1 hour. The reaction mixture was neutralized with 1 molar aqueous hydrochloric acid and concentrated to leave about 1.4 g of a white solid. This was dissolved in a methylene chloride-methanol mixture and purified by silica gel chromatography (methylene chloride / methanol = 7: 1 → 5: 1) to give 2-benzamido-2-deoxy-4,6-O-ethylidene- D-glucitol (compound (3), R ^{4 in} the formula)
Was 870 mg (yield 93%) of a methyl group and R ⁶ was a hydrogen atom. Melting point 165-167 ° C [α] _D ²³ -13.3 ° (c 0.65, CHCl ₃
/ CH ₃ OH = 1: 1) Rf value 0.35 (CH ₂ Cl ₂ / CH ₃ OH = 1: 1) ¹ H-NMR (CDCl ₃ / CD ₃ OD) δ 1.17 (3H, d, J = 4.9 Hz) , 3.
39 (1H, t, J = 10.8 Hz), 3.48 (1H, dd, J = 1.5, 9.3 H
z), 3.77 (3H, m), 4.11 (1H, dd, J = 5.3, 10.8 Hz),
4.22 (1H, m), 4.29 (1H, m), 4.65 (1H, q, J = 4.9 H
z), 7.44 (2H, m), 7.51 (1H, m), 7.82 (2H, m).

(Step 3) Compound (3) (wherein R ⁴ is a methyl group, R ⁶ is a hydrogen atom) 625 mg (2.0 mmol) is added with 10 ml of methylene chloride and 2.5 ml of triethylamine, and the mixture is cooled in an ice-salt bath.
Cooled to 15 ° C. 870 mg of methanesulfonyl chloride there
5 ml of a methylene chloride solution of (7.5 mmol) was added dropwise over 10 minutes. After stirring under ice-water cooling for about 2 hours, the orange-yellow reaction solution was further stirred overnight at room temperature. The reaction solution was diluted with 30 ml of methylene chloride, and 20 ml of ice water containing a small amount of sodium hydrogen carbonate was added to extract the organic layer. The aqueous layer was extracted with 20 ml of methylene chloride × 2 times, and the organic layers were combined and washed with water and 20 ml of saturated saline in this order. The organic layer was dried over sodium sulfate, filtered, and concentrated to dryness to leave about 1 g of an orange solid. By refining it by silica gel chromatography (methylene chloride / ethyl acetate = 3: 1), 840 mg of compound (4) (R in the formula, R ⁴ is a methyl group, R ⁶ is a hydrogen atom) (yield 93%) ) Got it. Melting point 161-164 ° C [α] _D ²³ -19.8 ° (c 0.65, CHCl ₃ ) Rf value 0.42 (hexane / AcOEt = 1: 1) IR (KBr) 164
0 cm ^{-1 1} H-NMR (CDCl ₃ ) δ 1.30 (3H, d, J = 5.0 Hz), 3.13 (3H,
s), 3.34 (3H, s), 3.63 (1H, dd, J = 10.2, 10.8 Hz),
3.90 (1H, dd, J = 2.2, 9.6 Hz), 4.48-4.56 (4H, m),
4.85 (1H, dt, J = 5.3, 9.7 Hz), 4.93 (1H, dt, J = 7.5,
10 Hz), 5.05 (1H, dd, J = 2.2, 7.1 Hz), 7.43 (2H,
m), 7.52 (1H, m), 7.92 (2H, m).

(Step 4) Compound (4) under nitrogen atmosphere
(R and R ⁴ in the formula are methyl groups, R ⁶ is a hydrogen atom) 360 mg
(0.8 mmol) was dissolved in 8 ml of methylene chloride, 0.7 ml of thiophenol was added, and the mixture was cooled in an ice bath. 2.4 ml (2.4 mmol) of a 1 molar methylene chloride solution of titanium tetrachloride was added to about 10
The mixture was added dropwise over 1 minute, and the stirring was continued for about 2 hours under ice cooling. Chloroform (5 ml) was added to the reaction solution suspended in brown to dilute it, and then cooled saturated aqueous sodium hydrogen carbonate solution 10
When ml was added little by little, the organic layer became almost colorless and the aqueous layer turned into a white suspension. Further, 5 ml of chloroform, 2 ml of methanol and 10 ml of an aqueous solution of sodium hydrogencarbonate were added to extract the organic layer, and the remaining aqueous layer was extracted with 20 ml of a mixture of 87:13 chloroform / methanol = 3 times. When the organic layer was dried over anhydrous sodium sulfate and then concentrated, 1.06 g of a pale yellow solid remained. Hexane / ethyl acetate =
When thoroughly washed with about 40 ml of a 4: 1 mixture, 280 mg of compound (5) (R in the formula is a methyl group) as a white solid (yield 83
%) Obtained. Melting point 150 ° C or higher (decomposition) Rf value 0.60 (AcOEt) ¹ H-NMR (CDCl ₃ / CD ₃ OD) δ 3.20 (3H, s), 3.26 (3H,
s), 3.99 (1H, dd, J = 3.9, 13.0 Hz), 4.12 (1H, dd, J =
3.6, 13.0 Hz), 4.29 (1H, dd, J = 2.5, 6.8 Hz), 4.57
(1H, d, J = 2.4 Hz), 4.59 (1H, s), 4.76-4.82 (2H,
m), 4.99 (1H, dd, J = 2.7, 4.4 Hz), 7.43 (2H, m), 7.
52 (1H, m), 7.91 (2H, m).

(Fifth Step) Compound (5) was added in a nitrogen atmosphere.
(R in the formula is a methyl group) 85 mg (0.2 mmol) and triphenylphosphine 160 mg (0.6 mmol) were added with toluene 6 ml and pyridine 0.1 ml (1.2 mmol). 102 mg of iodine (0.4
Mmol) was added in three portions, and the mixture was heated and stirred on an oil bath at 60 to 70 ° C. for about 1 hour. The reaction solution suspended in brown was allowed to cool, diluted with about 10 ml of ethyl acetate, and then 10 ml of a 5% aqueous sodium sulfite solution was added to rapidly discolor. After extraction with an ethyl acetate-water system, the organic layer was dried and concentrated to give a yellow solid.
280 mg remained. It was purified by silica gel chromatography (hexane / ethyl acetate = 3: 2) to obtain 42 mg (yield 68%) of compound (6) (R in the formula is a methyl group) as a white solid. Melting point 126-128 ° C [α] _D ²⁶ + 35.1 ° (c 0.90, CHCl ₃ ) Rf value 0.58 (haxane / AcOEt = 1: 2) ¹ H-NMR (CDCl ₃ ) δ 3.14 (3H, s), 3.90 ( 1H, broad),
4.53 (2H, m), 4.67 (2H, m), 4.76 (1H, t, J = 3.8 H
z), 5.36 (1H, dt, J = 1.4, 10.5 Hz), 5.56 (1H, dt, J
= 1.5, 17.1 Hz), 6.02 (1H, ddd, J = 5.2, 10.6, 17.1 H
z), 7.41 (2H, m), 7.50 (1H, m), 7.93 (2H, m).

(Sixth step) 69 mg (0.22 mmol) of compound (6) (R in the formula is a methyl group) was dissolved in 3 ml of methanol,
While cooling with ice, 43 mg (0.3 mmol) of potassium carbonate was added, and stirring was continued for 30 minutes under ice cooling and further for 5 hours at room temperature. While cooling with ice water again, 1 ml of a saturated aqueous solution of ammonium chloride was added for neutralization, 10 ml of ethyl acetate and 10 ml of diluted saline were added, and the mixture was stirred for a while. The layers were separated, and the organic layer was saturated saline solution (about 10%
After washing with ml, the aqueous layers were combined and extracted twice with 10 ml of ethyl acetate. The organic layers were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to dryness to give 48 mg of pale yellow oil.
The remaining. This was purified by silica gel chromatography (hexane / ethyl acetate = 3: 1) to obtain 42 mg (yield 88%) of compound (7) as a colorless solid. Melting point 38-40 ° C [α] _D ²⁶ + 159.6 ° (c 0.67, CHCl ₃ ) Rf 0.34 (hexane / AcOEt = 3: 1) ¹ H-NMR (CDCl ₃ ) δ 3.15 (1H, dd, J = 4.1, 8.3 Hz), 3.
63 (1H, dd, J = 4.2, 6.3Hz), 4.19 (1H, dt, J = 7.8, 9.
6 Hz), 4.53 (2H, m), 5.46 (1H, dt, J = 1.4, 10.5 H
z), 5.55 (1H, dt, J = 1.0, 17.1 Hz), 5.93 (1H, ddd,
J = 6.4, 10.6, 17.1Hz), 7.41 (2H, m), 7.50 (1H, m),
7.96 (2H, m).

(Seventh Step) Compound (7) was prepared in a nitrogen atmosphere.
To 43 mg (0.20 mmol) and cuprous cyanide 2 mg (0.02 mmol) were added anhydrous tetrahydrofuran 4 ml, and the mixture was cooled to -70 ° C in a dry ice-ethanol bath. There, 1.0 molar solution of dodecyl magnesium bromide in diethyl ether 0.4 ml
(0.40 mmol) was added dropwise over about 5 minutes, and the reaction solution became a yellow solution. After heating up to -10 ℃ for about 1 hour,
Neutralize by adding 2 ml of an aqueous solution of ammonium chloride, and add 20 ml of ethyl acetate and 10 ml of an aqueous solution of ammonium chloride to 0.
When stirred at around ℃, the water layer became pale purple. The layers were separated, the aqueous layer was extracted twice with 10 ml of ethyl acetate, the organic layers were combined, washed with 20 ml of brine, dried over magnesium sulfate, and concentrated to dryness to leave 135 mg of a white solid. It was purified by silica gel chromatography (hexane / ethyl acetate = 7: 2) to obtain 72 mg (yield 94%) of compound (8) as a colorless solid. Melting point 91-93 ° C [α] _D ²⁶ -1.8 ° (c 1.0, CHCl ₃ ) Rf 0.28 (hexane / AcOEt = 3: 1) ¹ H-NMR (CDCl ₃ ) δ 0.88 (3H, t, J = 6.7 Hz ), 1.26 (20
H, s-like), 1.38 (2H, m), 2.06 (2H, q, J = 6.9 Hz),
4.38 (3H, m), 4.55 (1H, d-like, J = 4.9 Hz), 5.44 (1
H, dd, J = 5.6, 15.4 Hz), 5.83 (1H, dt, J = 6.9, 15.4)
Hz), 7.36 (2H, m), 7.45 (1H, m), 7.86 (2H, m).

(Eighth step) (A) Compound (8) (46 mg, 0.12 mmol) was added to tetrahydrofuran.
Dissolve in 2.7 ml, add 2 ml of 2N hydrochloric acid at room temperature to 20
I stirred the time. 160 mg of sodium hydroxide (4.0 mg
Was added to 1.5 ml of water and 1.5 ml of ethanol, and the mixture was stirred at 95 ° C for 16 hours. After standing to cool, diluted hydrochloric acid water 10 ml
Was made weakly basic, and extraction was performed 3 times with about 15 ml of ether. The ether layer was dried over anhydrous sodium sulfate, filtered, and concentrated to leave 40 mg of a yellow wax. This was subjected to silica gel chromatography (ethyl acetate → methylene chloride / methanol = 9: 1 → methylene chloride / methanol /
25 mg of a natural sphingosine (compound (1), R ¹ , R ² , and R ³ in the formula are hydrogen atoms) as a white solid was obtained by purification with 2 molar aqueous ammonia = 40: 10: 1).
(Yield 70%) was obtained. Melting point 72-74 ° C [α] _D ²⁴ -1.2 ° (c 1.0, CHCl ₃ ) Rf 0.36 (CH ₂ Cl ₂ / MeOH / 2N-NH ₄ OH = 40: 10: 1) ¹ H-NMR (CDCl ₃ / CD ₃ OD) 0.88 (3H, t, J = 6.7 Hz), 1.25
(20H, s-like), 1.36 (2H, m), 2.06 (2H, q, J = 6.8 H
z)), 2.87 (1H, m) 3.67 (1H, m), 4.07 (1H, m), 5.45
(1H, dd, J = 6.9, 15.0 Hz), 5.75 (1H, dt, J = 7.5, 15.
0 Hz).

(Step 8) (B) Compound (8) 19 mg (0.05 mmol) was added to tetrahydrofuran.
Dissolve in 1.8 ml, add 2 ml of 2N hydrochloric acid at room temperature to 20
I stirred the time. The reaction mixture was ice-cooled and saturated aqueous sodium hydrogen carbonate solution was added to neutralize the reaction mixture.
1 ml of a THF solution of mg (0.46 mmol) was added over 5 minutes. 1 hour later, 100 ml (2.5 mmol) of sodium hydroxide aqueous solution (1 ml) was added, and further ethanol (1 ml) was added to the mixture on an oil bath at 90 ° C.
Heated for 2 hours. After cooling, the eighth step (A) of Example 1
10 mg (yield 70%) of sphingosine (compound (1), R ¹ , R ² , and R ³ in the formula are hydrogen atoms) as a white solid were obtained by performing the same post-treatment as shown in 1.
The physical property values were also in agreement.

[0048]

Reference Example 1 Sphingosine (compound (1), R in the formula)
21 mg (0.07 mmol) of ¹ , R ² and R ³ are hydrogen atoms were dissolved in 2 ml of methylene chloride, and 0.1 ml of pyridine and 0.1 ml of acetic anhydride were added while cooling with ice. The reaction was completed by adding 2 mg of dimethylaminopyridine with stirring at room temperature. The reaction solution was diluted with 10 ml of ethyl acetate, 10 ml of ice water containing a small amount of sodium hydrogen carbonate was added, and the mixture was stirred for a while. Ethyl acetate-
After performing a conventional extraction operation in an aqueous system, the organic layer was dried over magnesium sulfate and concentrated to leave 35 mg of a white solid. By purifying it by silica gel chromatography, 27 mg of N, O, O-triacetylsphingosine (R ¹ , R ² , and R ^{3 in the} general formula (1) are acetyl groups) was obtained as a colorless solid (yield 91%). ) Got it. Melting point 105-106 ° C [α] _D ²⁴ -12.9 ° (c 1.0, CHCl ₃ ) Rf value 0.25 (haxane / AcOEt = 1: 2) IR 3300, 1740,
1670, 1555 cm ^{-1 1} H-NMR (CDCl ₃ ) δ 0.88 (3H, t, J = 6.8 Hz), 1.25 (20
H, s-like), 1.33 (2H, m), 1.98, 2.06, 2.07 (each 3
H, each s), 2.02 (2H, m), 4.04 (1H, dd, J = 3.9 and
11.6 Hz), 4.30 (1H, dd, J = 6.0, 11.6 Hz), 4.43 (1H,
m) 5.28 (1H, t-like, J = 6.7 Hz), 5.39 (1H, dd, J =
7.4, 15.3 Hz), 5.70 (1H, d, J = 9.1 Hz), 5.83 (1H, d
t, J = 6.8, 15.3 Hz).

[0049]

[Reference Example 2] 50 mg (0.13 mmol) of compound (8) was dissolved in 2.7 ml of methanol, 0.3 ml of 2N hydrochloric acid was added, and the mixture was allowed to stand at room temperature.
Stirred for 20 hours. 20 ml of a mixed solution of 87:13 chloroform / methanol and 10 ml of water were added to the reaction solution, and the mixture was stirred for a while, then the layers were separated, and the aqueous layer was further extracted with 10 ml of a mixed solution of chloroform / methanol × 2 times. The organic layer is dried over sodium sulfate and then concentrated to give 1-O-benzoylsphingosine (R ¹ in the general formula (1) is a benzoyl group, R ² and R ²
55 mg of colorless oil mainly consisting of hydrochloride ( ³ is hydrogen atom) remained. This was dissolved in 3 ml of tetrahydrofuran, 60 mg (0.17 mmol) of palmitic acid succinimide ester and 20 mg of triethylamine were added, and the mixture was stirred at room temperature for 16 hours. To the reaction mixture was added 1 ml of 1N aqueous sodium hydroxide solution,
The mixture was stirred at room temperature for 3 hours, neutralized with diluted hydrochloric acid, added with 20 ml of methylene chloride and 10 ml of water, and stirred for a while. After separating the layers, the aqueous layer was extracted twice with 10 ml of methylene chloride. The organic layer was dried and then concentrated to leave 110 mg of a white solid. This was purified by silica gel chromatography (methylene chloride / methanol = 40: 1) to give 58 mg of N-palmitoylsphingosine (R ¹ and R ³ in the general formula (1) are hydrogen atoms, and R ² is palmitoyl group). Yield 83%) was obtained. Melting point 90-92 ° C [α] _D ²⁴ -3.0 ° (c 1.0, CHCl ₃ ) Rf value 0.36 (AcOEt) IR (KBr) 3330, 1655, 1555 cm
^{-1 1} H-NMR (CDCl ₃ ) δ 0.88 (6H, t, J = 6.7 Hz), 1.17-
1.40 (48H, broad s), 2.05 (2H, q, J = 6.9 Hz), 2.23
(2H, t, J = 7.6 Hz), 2.65 (2H, broad s), 3.69 (1H,
m), 3.90 (2H, m), 4.32 (1H, m), 5.53 (1H, dd, J = 6.
4, 15.3 Hz), 5.78 (1H, dt, J = 6.6, 15.3 Hz), 6.22 (1
H, d J = 7.6 Hz).

[0050]

According to the present invention, natural sphingosine and ceramide can be obtained on the gram scale. Since methods for synthesizing glycosphingolipids from these compounds and their precursor compounds (8) have already been established,
The present invention also makes it possible to obtain the glycolipids relatively easily, and is expected to be useful for elucidating their functions and applying them to the medical field. Also, by introducing various hydrophilic groups into the hydroxyl groups of ceramide, a wide range of functional surfactants and amphipathic substances can be easily obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a production process of natural sphingosines.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C07D 319/20 413/06 319 // C07B 61/00 300

Claims (7)

[Claims] 1. Using N-benzoyl-D-glucosamine as a starting material, the following general formula (1): In the method for producing a natural sphingosine represented by the formula (wherein R ₁ , R ² and R ³ represent a hydrogen atom),
(I) N-benzoyl-D-glucosamine is reacted with an acetalizing agent to give a compound represented by the general formula (2): (In the formula, Bz is a benzoyl group, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, or an optionally substituted phenyl group, R 4
⁶ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R ⁴ and R ⁶ have 4 to 4 carbon atoms bonded to their ends.
The first step for obtaining 4,6-acetal represented by (indicating 7 methylene groups), (ii) 4, obtained in the first step
By reducing 6-acetal, the following general formula (3): (In the formula, Bz, R ⁴ , and R ⁶ have the same meanings as described above) The second step for obtaining the 2-benzamido-2-deoxy-D-glucitol derivative, (iii) the step for obtaining The 2-benzamido-2-deoxy-D-glucitol derivative thus obtained was sulfonylated and oxazolineized at the same time to give a compound represented by the following general formula (4): (In the formula, Ph represents a phenyl group, R represents an alkyl group having 1 to 4 carbon atoms or an aryl group which may be substituted, and R ⁴
And R ⁶ has the same meaning as described above), the third step of obtaining a phenyloxazoline derivative represented by
The faenyloxazoline derivative obtained in the step is deacetalized to give the following general formula (5): (In the formula, Ph and R have the same meanings as described above) Fourth step for obtaining a diol compound, (v) Iodination of the diol compound obtained in the fourth step and reductive elimination at the same time Then, the following general formula (6): (Wherein Ph and R have the same meanings as described above), a fifth step of obtaining a terminal vinyl compound, (vi) the fifth step
The vinyl compound obtained in the step is treated with a base to give a compound represented by the following general formula (7): A sixth step of obtaining an epoxide represented by the formula: wherein Ph has the same meaning as described above, and (vii) reacting the epoxide obtained in the sixth step with a dodecyl Grignard reagent in the presence of a monovalent copper salt. Then, the following general formula (8): (Wherein Ph has the same meaning as described above), a seventh step for obtaining a dodecyl group-containing compound, (viii) the seventh step
Eighth step of cleaving the oxazoline ring of the dodecyl group-containing compound obtained in the step under acidic conditions and eliminating the benzoyl group to obtain a natural sphingosine represented by the general formula (1). A method for producing natural sphingosine, which comprises: 2. The following general formula (7): An epoxide represented by the formula (wherein Ph represents a phenyl group) is reacted with a dodecyl Grignard reagent in the presence of a monovalent copper salt, and the following general formula (8): (In the formula, Ph has the same meaning as described above) A method for producing a dodecyl group-containing compound. 3. The following general formula (3): (In the formula, Bz, R ⁴ , and R ⁶ have the same meanings as described above) A 2-benzamido-2-deoxy-D-glucitol derivative. 4. The following general formula (4): (In the formula, Ph represents a phenyl group, R represents an alkyl group having 1 to 4 carbon atoms or an aryl group which may be substituted, and R ⁴
And R ⁶ have the same meaning as described above). 5. The following general formula (5): (In the formula, Ph and R have the same meaning as described above). 6. The following general formula (6): (In the formula, Ph and R have the same meanings as described above), and a terminal vinyl compound. 7. The following general formula (7): (In the formula, Ph has the same meaning as described above).