CN104497064B - α galactosyl ceramides Novel isomeric and its synthetic method - Google Patents

Abstract

The invention provides a kind of α galactosyl ceramides Novel isomeric and its synthetic method, 4,5 cis-double bonds sphingol chains are changed into the configuration of sphingol chain.Present invention reduces reactions steps, yield is improved, post processing and the purification step of some steps is eliminated, available for the fully synthetic of similar glycosyl ceramide, the extensive research and development application of different glycosyl ceramides is met.

Description

New isomer of α-galactosylceramide and its synthesis method

technical field

The invention belongs to the field of total synthesis of glycolipid molecules, in particular to a new isomer of α-galactosylceramide and a synthesis method thereof.

Background technique

In the 90s of the 20th century, Kirin Breweries et al. found that the extract of Agelas mauritianus sponge contained active molecules, and the structure of compound a after synthesis was shown in Figure 1 (a-galactosylceramide, a-GalCer, KRN7000) had immunological biological activity. α-Galactosylceramide (KRN 7000) is the most famous member of the glycosylceramide (glycosphingolipid) family, which is recognized by the antigen-presenting molecule CD1d to form a binary complex, and then binds to the NKT cell receptor (TCR ) interaction, activate the signal transmission molecules responsible for intercellular communication, namely cytokines, and the cytokine Th1/Th2 immune response activates specific other immune cells (B cells, T cells, macrophages, etc.) to play anti-tumor and antibacterial functions ( Th1) or protect the body against autoimmune diseases (Th2). The clinical research of KRN7000 is not very successful, mainly because KRN7000 simultaneously produces Th1 and Th2 immune responses against each other, and another disadvantage is overstimulation; it is necessary to develop new KRN7000 analogs that can selectively and appropriately activate NKT cells Th1 or Th2 immune responses are preferentially generated.

Due to the promising wider application prospects and existing defects of KRN 7000, it has attracted many research groups in the past ten years to find new α- Galactosylceramide homologue.

After consulting, there are few reports on the molecular activity of sphingosine chain (Sphingosine chain, see compound a in Figure 1) after the configuration change. Previous studies are all about 4,5 trans double bond sphingosine chain derivatives synthesis (see Figure 1, compounds c, e), but the 4,5 cis double bond sphingosine chain derivatives of the synthesized α-galactosylceramide (see Figure 2, compounds 1a, 1b, 1c) have not yet See report.

Due to the special design of the 4,5-cis sphingosine chain of the cis isomer of α-galactosylceramide, it is necessary to independently synthesize (2S,3R,4Z)-2-azido-1,3-diol derivatives . Sphingosine with multiple chiral centers is the key to all studies on glycosphingolipid synthesis, and it is also the bottleneck in the study of glycolipid molecule synthesis. The Chiron Approach uses the chiral compound D-galactose to contain part of the chiral structure of sphingosine, and then performs Wittig olefination to control the C4-C5 double bond stereoscopically. The key group at the 2-position of the aminoalcohol undergoes an azide reaction and transforms into the desired 2S configuration.

The high stereoselective synthesis of a-glucoside of galactosylceramide is also the key and difficulty of total synthesis. According to the Armed-disarmed strategy, the theoretical basis is based on the difference in the electronic effect of the sugar ring and its substituents on the ring, which leads to the difference in the reactivity of the sugar group, thereby realizing the selective condensation of glycosidation. The choice of glycosylation is closely related to the nature and structure of the sugar acceptor. In the past, benzyl trichloroacetimide sugar ester was used to synthesize α-sugar groups. Since the activity of trichloroacetimide ester is not very high, it is generally required to protect the group except the 1-position of sugar acceptor sphingosine. The benzyl group needs catalytic hydrogenation, so it is not suitable for the molecule we designed; it is reported that the benzyl iodide sugar reaction can also be α-glycosylated, and it is also faced with the debenzylation reaction; when selecting the protecting group of the sugar, we use the protecting group trimethylsilyl (TMS). Iodosugars were considered too reactive and unstable to be used in synthesis. But over the past decade, several studies have convincingly disproved this notion and led to a renaissance in the chemistry of glycosyl iodides. Glycosyl iodides are not only effective but also have unique control over the stereo direction of the reaction, which can be reflected in the synthesis of C-O chains with high stereoselectivity. Using iodosugars, through the in situ anomerization reaction proposed by Lemieux, from α-iodides to more active β-iodides, using iodides to preferentially generate more reactive β-iodides in situ Isomerization, followed by a combination of reactions similar to SN2 substitution, α-position stereoselectivity can be achieved. These reactions are orders of magnitude faster than those of bromosugars under equivalent conditions, and only the α-isomer is formed.

Each α-galactosylceramide new isomer of the present invention needs 14 steps of reaction including intermediates; the total synthesis steps of the α-galactosylceramide new isomer of the prior art are more than those of the present invention There are at least 6 more steps; the present invention not only obtains new isomers, but also realizes the full synthesis route of new isomers.

Contents of the invention

In order to solve the above technical problems, the present invention provides a new isomer of α-galactosylceramide and its synthesis method.

A new isomer of α-galactose ceramide is characterized in that the configuration of the sphingosine chain is changed to a 4,5 cis double bond sphingosine chain.

The new isomer of α-galactosylceramide is characterized in that its acyl chain has one or more cis double bonds.

The synthetic method of a new isomer of α-galactosylceramide is characterized in that it comprises the following steps:

1) Construction of 4,5-cis sphingosine:

The raw material uses galactose as a chiral source. In the first step, acetal is formed to protect the 4 and 6 hydroxyl groups of galactose; in the second step, an aldehyde group is formed at the 3 hydroxyl to remove the carbons at the 1 and 2 positions of the sugar. ; The third step uses the Wittg reaction to react with the pre-synthesized tetradecylphosphorus ylide to obtain 4,5-cis-alkene; the fourth step is to carry out azidation on the original 5-position hydroxyl on the carbon, and a carbon The desired configuration is obtained by configuration inversion; the fifth step is deketalization reaction to obtain (2S,3R,4Z)-2-azido-1,3-diol derivatives.

2) Synthesis of new isomers of α-galactosylceramide:

First, sugar donors are synthesized, and full TMS galactose is synthesized from galactose. After simple treatment, TMS iodine sugar is obtained after reacting with iodine reagent. Without post-treatment, it immediately reacts with sugar acceptor-sphingosine under the action of a catalyst to obtain A single α-glycosyl isomer; then remove TMS on galactose under mild and simple conditions; the azide on the obtained compound is converted into an amino group, and because the compound is very active, it is directly put into the next step; the final amide reaction adopts The carboxylic acid is firstly derivatized into an active ester, and then reacted with an amino group to obtain a new isomer of α-galactosylceramide with mild conditions and a reasonable yield.

The beneficial effects of the present invention are as follows: (1) TMS iodized sugar has high activity as a sugar donor, and the 3-hydroxyl of sphingosine can undergo glycosylation without protection, eliminating protection and deprotection steps, so that the original The classic route is shortened by 4 steps; (Figure 3, 4) (2) The α-glycosyl isomer becomes a specific product, and the yield increases; (3) Trimethylsilane TMS is used as the protecting group, so that the protecting group The reaction, iodination, and α-glycosylation reactions can be performed in one pot, so many post-treatment and purification steps are omitted; (4) If benzyl iodide sugar or benzyl trichloroacetimidoglycoside is used for α - Glycosylation must face the final step of catalytic hydrogenation. The original catalytic hydrogenation operation required pressure-resistant equipment and dangerous hydrogen, which was not environmentally friendly and costly; but we only need to use weak acid to remove TMS. Affects the double bonds in the molecules we design. (5) The one-pot α-glycosylation route of TMS iodized sugar and this 4,5-cis-sphingosine has not been reported yet. The success of this type of α-glycosylation is the key to the invention; (6) The total synthesis of the new isomer of α-galactosylceramide was shortened by 6 steps compared with the previous total synthesis route. The key α- The one-pot method of glycosylation in one step, together with the simplification of the reaction conditions for the removal of TMS groups, reduces the synthesis cost of glycoceramide and reduces the difficulty of operation, which provides a material basis for its application in biology, cosmetics and other aspects; (7) The synthetic route of the present invention can be used for the total synthesis of similar glycoceramides, satisfying the extensive research and application of different glycoceramides.

Description of drawings

Figure 1 is a diagram of the structure of the reported α-galactosylceramide isomer and the dominant cytokine induction;

Figure 2 is a structural diagram of the new isomer of α-galactosylceramide (1a-1c) of the present invention;

Fig. 3 is 4,5-cis sphingosine synthetic route map;

Figure 4 is a synthesis route diagram of sugar donor synthesis and new isomers of α-galactosylceramide;

Figure 5 is a synthesis diagram of active esters.

detailed description

Example 1

Construction of 4,5-cis sphingosine (see Figure 3)

The raw material uses galactose with a relatively cheap structure as a chiral source. In the first step, acetal is formed to protect the 4 and 6 hydroxyl groups of galactose; in the second step, an aldehyde group is formed at the 3 hydroxyl, and the carbons at the 1 and 2 positions of the sugar are removed; in the third step, the Wittg reaction is used to react with Pre-synthesized tetradecylphosphorus ylide reaction to obtain 4,5-cis-alkene, which is a relatively critical step; the fourth step is to azidize the original 5-position hydroxyl on the carbon, and a carbon configuration occurs at this position Invert to obtain the desired configuration; the fifth step is deketalization reaction to obtain (2S,3R,4Z)-2-azido-1,3-diol derivatives.

The reported compounds were identified by mass spectrum or hydrogen spectrum; the new compounds were determined by nuclear magnetic resonance hydrogen spectrum, carbon spectrum and mass spectrum.

1) Synthesis of 4,6-O-benzylidene-D-galactose (3)

Add D-galactose (20g, 111mmol), p-toluenesulfonic acid (2g, 11.6mmol), PhCH(OCH ₃ ) ₂ (23mL, 154mmol) into 80mL of anhydrous DMF, and rotate the turbid solution on a rotary evaporator, The temperature was set at 50°C. After 4h, the rotary evaporation was stopped. The reaction was quenched by adding 2 mL of triethylamine, and then the solvent DMF was evaporated to dryness. The white product (10.4 g, 70%) was separated and purified by column chromatography. (Since it is a known compound, it is only identified by mass spectrometry. The same below) ESI-MS: m/z [M + H]+ 269.2.

2) Synthesis of 4,6-O-benzylidene-D-threose (4)

Add 4,6-O-benzylidene-D-galactose 3 (8.65g, 32.2mmol) into 600mL pH=7.6 buffer solution just prepared, and stir vigorously at 40°C. Dissolve NaIO ₄ (16g, 74.8mmol) in a small amount of buffer solution, and slowly add it dropwise into the reaction solution with a dropping funnel (it takes about 3 hours). During this period, adjust the pH of the reaction solution to neutral with 0.1mol/L NaOH from time to time . After the dropwise addition was completed, the reaction was continued for 3 h. The reaction solution was evaporated to dryness, then extracted with tetrahydrofuran, then dried by adding anhydrous MgSO ₄ , filtered with suction, the filtrate was rotary evaporated, sucked to dryness, and weighed. The product was obtained (6.1480 g, 53.9%). ESI-MS: m/z [M ⁺ H]+209.1.

3) Synthesis of triphenyltetradecylphosphonium bromide (14)

Add PPh ₃ (12.4 g, 47.3 mmol) and CH ₃ (CH ₂ ) ₁₂ CH ₂ Br (1-bromotetradecane) (14.5 g, 52.3 mmol) into a round bottom flask, 140 ° C oil bath, reflux state Under the reaction 8h. The yellow viscous liquid in the round bottom flask is poured into a beaker while it is hot (it will solidify when the temperature is lowered), and an appropriate amount of ether is added, stirred vigorously, a white solid appears, filtered, the filter residue is drained, and stored in the dark to obtain White solid 14 (23.67 g, 87%). Since mass spectra were not readily available, compounds were identified by hydrogen NMR spectroscopy. ¹ H NMR (400MHz, CDCl ₃ ) δ 7.80-7.40 (m, 15H, 3×C ₆ H ₅ ), 3.62 (m,2H, CH ₂ -P+Ph3), 1.45 (m, 2H, CH ₂ -CH ₂ -P+Ph3), 1.02 (m, 20H, (CH ₂ )10), 0.69 (t, 3H, CH ₃ ).

4) Synthesis of (2R,3R,4Z)-1,3-O-benzylidene-4-octadecene-1,2,3-triol (5)

Dissolve Ph ₃ PCH ₂ (CH ₂ ) ₁₂ CH ₃ Br (4.13 g, 7.67 mmol) in anhydrous THF (20 ml), slowly add n-BuLi (6.8 ml, 2.5 M hexane solution), the reaction solution was first orange, and reacted at 0°C for 30 minutes. Add 4,6-O-benzylidene-D-threose 4 (1.18 g, 5.67 mmol ) into anhydrous THF (6ml) to dissolve, and slowly drop it into the reaction solution at 0°C until the addition is complete Afterwards, react at low temperature for 10 minutes. Transfer to room temperature and react for 4 hours. The reaction was quenched by adding MeOH (50 mL), water (100 mL). Evaporate to dryness, and separate and purify the product by column chromatography. The product 5 was obtained (0.99 g, 45%). ESI-MS: m/z [M + H] ⁺ 389.3.

5) Synthesis of (2S,3R,4Z)-1,3-O-benzylidene-2-azido-4-octadecene-1,3-diol (6)

Take compound 5 (2.5 g, 6.44 mmol), add anhydrous dichloromethane (20 mL) and anhydrous pyridine (1 mL) sequentially. At -15°C, trifluoromethanesulfonic anhydride (1.38 ml, 7.8 mmol) was slowly added dropwise, and stirred at constant temperature for 15 min after the addition was complete. Anhydrous DMF (62 mL) and sodium azide (2.1 g, 32.2 mmol) were mixed and quickly added dropwise to the reaction solution, and the reaction was carried out at a constant temperature of 40°C for 6 h. After the reaction was almost complete, water (50 mL) was added to quench the reaction, and then extracted several times with dichloromethane. The organic phase was dried with anhydrous MgSO ₄ , then evaporated to dryness, and the product was separated and purified by column chromatography. Product 6 (2.24 g, 85%) was obtained. ¹ H NMR (400MHz, CDCl ₃ ) δ 7.52 (dd, J = 7.5, 1.6 Hz, 2H), 7.45-7.34 (m, 3H), 5.86 (d, J = 11.0 Hz, 1H), 5.62-5.48 (m , 2H), 4.47 (t, J = 9.1 Hz, 1H), 4.39 (dd, J =11.1, 5.2 Hz, 1H), 3.67 (t, J = 10.9 Hz, 1H), 3.54 (dd, J = 9.6, 5.2 Hz, 1H),2.34-2.23 (m, 2H), 1.49 (dd, J = 9.7, 5.3 Hz, 2H), 1.34 (d, J = 20.1 Hz,20H), 0.94 (t, J = 6.8 Hz, 3H). ¹³ C NMR (101 MHz, CDCl ₃ ) δ 137.98, 137.53,129.28, 128.48, 126.34, 125.82, 101.26, 76.73, 69.31, 57.65, 32.14, 29.90,29.88, 29.83, 29.72, 29.59, 29.49, 28.50, 22.91, 14.34. ESI-MS: m/z [M + H] ⁺ 414.3.

6) Synthesis of (2S,3R,4Z)-2-azido-4-octadecene-1,3-diol (7)

Compound 6 (0.4 g, 0.97 mmol) was pumped dry, anhydrous dichloromethane (4 mL) and MeOH (12 mL) were added, then APTS (15 mg) was added, and stirred at 40°C for 2 days. After the reaction was almost complete, NaHCO ₃ solution was added to make the reaction solution neutral, extracted with dichloromethane (3×30 ml), the organic phase was dried with anhydrous magnesium sulfate, and the product was separated and purified by column chromatography. Product 7 (0.31 g, 98%) was obtained. ¹ H NMR (400 MHz, CDCl ₃ ) δ 5.69 (d, J = 10.4 Hz, 1H), 5.47 (t, J = 10.4 Hz, 1H), 4.60 (d, J = 8.0 Hz, 1H), 3.85-3.74 (m, 2H), 3.51(d, J = 4.7 Hz, 1H), 2.41 (s, 2H), 2.11 (dt, J = 15.2, 7.5 Hz, 2H), 1.43-1.15(m, 22H), 0.88 ( t, J = 6.7 Hz, 3H). ¹³ C NMR (101 MHz, CDCl ₃ ) δ 135.97, 127.85,68.36, 67.19, 62.74, 32.12, 29.86, 29.80, 29.71, 29.56, 29.51, 28.389, ESI 22. - MS: m/z [M + H] ⁺ 326.3.

Example 2

Synthesis of new isomers of α-galactosylceramide (see Figure 4)

First, sugar donors are synthesized, and full TMS galactose is synthesized from galactose. After simple treatment, TMS iodine sugar is obtained after reacting with iodine reagent. Without post-treatment, it immediately reacts with sugar acceptor-sphingosine under the action of a catalyst to obtain A single α-glycosyl isomer; then remove TMS on galactose under mild and simple conditions; the azide on the obtained compound is converted into an amino group, and because the compound is very active, it is directly put into the next step; the final amide reaction adopts The carboxylic acid is firstly derivatized into an active ester, and then reacted with an amino group to obtain a new isomer of α-galactosylceramide with mild conditions and a reasonable yield. The new compounds were determined by H-NMR and C-NMR spectra, and the final identification of the main compounds was by high-resolution mass spectrometry.

1) Synthesis of 1,2,3,4,6-penta-O-trimethylsilyl-α-D-galactopyranose (8)

Add D-galactose (1.8g, 10mmol), add pyridine (90mL), hexamethyldisilazide (18mL, 86mmol), TMSCl (9ml, 70mol) under nitrogen protection, heat to 75°C, react for 1h, then cool to room temperature. The reaction solution was poured into 100ml of ice water, extracted with cyclohexane (3×60mL), the organic layers were combined, washed with water (3×50 mL), dried and spin-dried to give anhydrous oil 8 (5.11g, 94.5%) . ESI-MS: m/z [M ⁺ H]+541.2.

2) Synthesis of 2,3,4,6-tetra-O-trimethylsilyl-α-D-galactopyranose iodine (9)

Add D-galactose 8 (2.0 g, 3.69 mmol 500 mg, 0.91 mmol) substituted by TMS, add anhydrous dichloromethane (4 ml) under nitrogen protection, cool the system to 0 ^o C, add TMSI (125 µL, 0.91 mmol) After 20 minutes, anhydrous toluene was added, the solvent was recovered under reduced pressure to obtain a yellow oil, and anhydrous benzene (2 mL) was added for later use. (Because compound 9 is very reactive, no post-treatment was performed, and the resulting solution was directly subjected to the next reaction).

3) (2,3,4,6-tetra-O-trimethylsilyl-α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-azido Synthesis of -4-octadecene-l,3-diol (10)

The obtained compound 7 was dissolved in anhydrous benzene (225mg, 0.675mmol), and then 4 Å molecular sieves (250mg), tetra-n-butylammonium iodide (750mg, 2.03mmol), N, N-diisopropylethyl Amine (250 μL, 1.42 mmol). Stirring was carried out at 50° C. for 30 minutes, a benzene solution of compound 9 was added dropwise within 20 minutes, and then stirred overnight. Stop the reaction, filter out molecular sieves, evaporate the solvent to dryness, add CH ₂ Cl ₂ (10 mL) and water (10 mL) to obtain the organic phase, rotary evaporate to dryness, and column chromatography to obtain a white solid (0.36 g, 67%) . ¹ H NMR (400 MHz, CDCl ₃ ) δ 5.62 (dd, J = 11.3, 7.4 Hz, 1H), 5.40 (t, J = 10.1 Hz, 1H), 4.75 (d, J = 3.1 Hz, 1H), 4.33 (t, J = 8.3 Hz,1H), 4.02-3.85 (m, 1H), 3.75 (dd, J = 12.3, 7.1 Hz, 1H), 3.69 (t, J = 9.7 Hz,2H), 3.58 (d, J = 9.2 Hz, 1H), 3.50 (d, J = 8.6 Hz, 1H), 3.39-3.33 (m, 2H), 2.11 (dd, J = 14.3, 7.1 Hz, 2H), 1.65 (s, 1H), 1.43-1.32 (m, 2H), 1.24 (s, 20H), 0.86 (t, J = 6.4 Hz, 3H), 0.18 (s, 9H), 0.16 (s, 9H), 0.14 (s, 9H), 0.12 (s, 9H). ¹³ C NMR (101 MHz, CDCl ₃ ) δ 134.86 (CH=CH), 127.36 (CH=CH), 100.37 (C-1), 77.33, 73.97, 73.42, 73.17, 71.34, 65.48, 62.76, 61.21, 31.82,29.55, 29.48, 29.42, 29.31, 29.25, 27.96, 22.58, 14.01, 1.08, 0.94, ^0.77,0.62 , 0.03-0. :798.4736).

4) Synthesis of (α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-azido-4-octadecene-l,3-diol (11)

Compound 10 (1.44 g, 18.55 mmol) was dissolved in methanol (20 mL), APTS (20.0 mg), 10 mL of MeOH, and 4 mL of dichloromethane were added, and reacted at room temperature for 5 hours. After the reaction was completed, NaHCO ₃ (100mg) was added to neutralize, filtered, evaporated to dryness, and purified by column chromatography to obtain a white solid (860 mg, 95%). ¹ H NMR (400 MHz, MeOD) δ 5.75-5.58(m, 1H), 5.55-5.40 (m, 1H), 4.89 (d, J = 3.4 Hz, 1H), 4.56 (dt, J = 14.6, 7.3Hz , 1H), 4.00-3.90 (m, 2H), 3.88 (t, J = 6.0 Hz, 1H), 3.85-3.74 (m, 2H),3.75-3.67 (m, 2H), 3.67-3.58 (m, 1H ), 3.54 (td, J = 6.5, 3.2 Hz, 1H), 3.32 ,2.25-2.06 (m, 2H), 1.41 (d, J = 6.7 Hz, 2H), 1.30 (s, 20H), 0.96-0.86 ( m,3H). ¹³ C NMR (101 MHz, MeOD) δ 134.10 (CH=CH), 128.04 (CH=CH), 99.76 (C-1),71.20, 69.87, 69.54, 68.65, 67.53, 66.14, 65.94, 61.21, 31.62, 29.46-29.18, 29.00, 27.44, 22.28, 13.05. ESI-HRMS: m/z [M + Na] ⁺ 510.3187 (cacl:510.3155).

5) Synthesis of (α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-amino-4-octadecene-l,3-diol (12)

Compound 11 (35 mg, 0.072 mmol) was dissolved in 5 mL of methanol, and trimethylphosphine (26.7 µL, 0.252 mmol) was added dropwise, and reacted at room temperature for 2 h. After concentration, the by-product Me ₃ PO was removed by vacuum at 30°C. A white solid (32 mg, quantitative conversion) was obtained, which was unstable due to the active wave of the product, and was directly put into the next step reaction without further purification.

6) (α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-octadecylamido-4-octadecene-l,3-diol (1a) Synthesis

Active ester 13a (56.3 mg, 0.144 mmol) was dissolved in THF (2 mL), and amine 12 (32 mg, 0.069 mmol) obtained in the previous step and triethylamine (55 µL, 0.395 mmol) were added. The reaction was carried out at room temperature for 10 hours. Ethyl acetate (5 mL) was added, and after post-treatment, the product was separated and purified by column chromatography (CH ₂ Cl ₂ /MeOH: 20/1). Obtained as a white solid (35mg, 69%). ¹ H NMR (400 MHz, C ₅ D ₅ N) δ 8.40 (d, 1H, J =9.8 Hz, –NH– ), 5.95-5.88 (m, 1H, H-4'),5.59 (1 H, dd , J = 11.3, 7.3 Hz, H-5'), 5.38 (d, 1 H, J = 3.7 Hz, H-1), 5.10(m, 1H, H-3'), 4.67 (d, 1H, J = 2.7 Hz, H-2'), 4.55–4.24 (8 H, m, H-1', H-2,H-3, H-4, H-5, H-6), 2.37 (2 H, t, J =7.4 Hz, H-2"), 2.24 (2 H, ddd, J =22.1,14.7 , 7.0 Hz, H-6'), 1.76 (2 H, dt, J =14.6 Hz, 7.4 Hz, H-3”), 1.36-1.18 (52H, m, CH ₂ ), 0.88 (6 H, dd, J =6.8, 5.5 Hz, 2×CH ₃ ). ¹³ C NMR (101 MHz, C ₅ D ₅ N ) δ 174.85 (CONH), 133.69 (CH, CH=CH), 133.05 (CH, CH=CH), 103.24 (CH, anomericC), 73.85, 72.68, 72.05, 71.57, 70.44 (C-2, C-3, C-4, C-5, C-6), 69.56 (CH,C-3'), 63.81(CH ₂ , C-1'), 56.35(CH, C-2'), 37.96 (CH ₂ ,C -2”), 33.32, 31.30,31.16, 31.10, 30.96, 30.89, 30.79, 29.35, 27.45, 24.11 (CH ₂ , alkyl chain),15.48 (CH ₃ , 2×CH ₃ ). ESI-HRMS: m/z [M + H] ⁺ 728.6032 (cacl:728.6040).

Example 3

Synthesis of (α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-octadecylamido-4-octadecene-l,3-diol (1b)

The synthesis method is the same as 1a, except that compound 13b is used instead of compound 13a to obtain a white solid with a yield of 67%. ¹ H NMR (400 MHz, MeOD: CDCl ₃ = 1:3) δ 7.43 (1 H, s, CONH) 5.52 (1 H, dt, J =11.1, 7.5Hz, H-5'), 5.33 (dd, 3 H, J =20.6, 8.1 Hz, H-4', H- 9", H-10"), 4.86 (1 H, d, J =3.5 Hz, H-1), 4.41 (d, 1 H, J =7.9 Hz, H- 3'), 3.97-3.86 (m, 2 H, H-2', H-3), 3.79-3.66 (m, 7 H, H-1', H-2, H- 4, H-5, H-6), 2.15 (t, 2 H, J =7.5 Hz, H-6'), 2.00 (dd, 4 H, H-8”, H-11”), 1.56 (s , 1H, H-7'), 1.25 (m, 43 H, CH ₂ ),0.84 (t, 6 H, J =6.5 Hz, 2×CH ₃ ). ¹³ C NMR (101 MHz, MeOD: CDCl ₃ = 1:3) δ 174.47(CONH), 133.70 (CH, CH=CH), 129.57 (CH, CH=CH), 129.31 (CH, CH=CH), 128.55(CH, CH=CH), 99.67 (CH, anomeric C), 70.35, 69.92, 69.40, 68.69, 67.25 (C-2,C-3, C-4, C-5, C-6), 66.99(C-3'), 61.42(C-1') , 53.66(CH, C-2'), 48.89(CH ₂ , C-6'), 48.68, 48.47, 48.25, 48.04, 47.83, 47.61, 36.06, 31.51, 29.28, 29.23,29.09, 28.99, 28.93, 2 28.81, 27.36, 26.78(CH ₂ ), 25.45(CH ₂ , C-7'), 22.23(CH ₂ ), 13.46(2×CH ₃ ). ESI-HRMS: m/z [M + Na] ⁺ 748.5680 ( cacl:748.5703).

Example 4

Synthesis of (α-D-galactopyranose)-(1→1)-(2S,3R,4Z)-2-octadecylamido-4-octadecene-l,3-diol (1c)

The synthesis method is the same as that of 1a, except that compound 13c is used instead of compound 13a to obtain a white solid with a yield of 65%. ¹ H NMR (400 MHz, MeOD: CDCl ₃ = 1:3) δ 5.60-5.48 (m, 1 H, H-5'), 5.43-5.27 (m, 5 H, H-4', H-9” , H-10”, H-12”, H-13”), 4.91 (1 H, d, J =3.3 Hz, H-1), 4.48 (t, 1 H, J =8.5 Hz, H-3' ), 3.99 (dd, 1 H, J =10.1, 6.1 Hz, H =2'), 3.90 (d, 1 H, J =2.2 Hz, H-2), 3.85-3.76 (m, 5 H, H - 1', H-3, H-4, H-5), 3.71 (dd, 2 H, J =5.9, 3.5 Hz, H-6), 2.78 (t, 2 H, J =6.2 Hz, H-11 ”), 2.19 (dd, 2 H, J =13.7,6.1 Hz, H-6’), 2.07 (dd, 4 H, J =13.5, 6.7 Hz, H-8”, H-14”), 1.60 ( s, 2 H, H-7'), 1.48 -1.17 (m, 38 H, CH ₂ ), 0.96-0.83 (m, 6 H, 2×CH ₃ ). ¹³ C NMR (101 MHz,MeOD: CDCl ₃ = 1:3) δ 174.62 (CONH), 133.33 (CH, CH=CH), 129.48 (CH, CH=CH),129.40 (CH, CH=CH), 127.63(CH, CH=CH), 127.56 (CH , CH=CH), 99.85 (CH,anomeric C), 71.01, 69.96, 69.54, 68.84, 66.69 (C-2, C-3, C-4, C-5, C-6),66.07 (C-3 '), 61.26 (C-1'), 54.00 (C-2'), 35.86 (CH ₂ , C-6'), 31.61 (C-8"),31.19 (C-12"), 29.50, 29.35, 29.09, 29.00, 28.95, 28.87, 27.36, 26.75, 26.71,25.58, 25.10, 22.27, 22.16 (CH ₂ ), 13.03 (CH ₃ , 2×CH ₃ ). ESI-HRMS: m/z [M + Na] ⁺ 746.5531 (cacl:746.5547).

Example 5

Synthesis of active ester (see Figure 5)

1) Synthesis of 2,5-dioxo-tetrahydropyrrole-1-stearate (13a)

Stearic acid (1.00 g, 3.52 mmol) was dissolved in THF (10 mL), and dicyclohexylcarbodiimide (870 mg, 4.22 mmol) and N-hydroxysuccinimide (802 mg, 7.04 mmol) were added at 35 °C for 15 hours, poured the reaction solution into water (20 mL), extracted with CH ₂ Cl ₂ (20 mL), washed the organic phase with saturated brine (20 mL), dried over MgSO4, filtered, concentrated, and the column layer The product was isolated and purified by analysis to obtain a white solid (1.14 g, 85%). ESI-MS: m/z [M ⁺ H]+382.5.

2) Synthesis of 2,5-dioxo-tetrahydropyrrole-1-oleate (13b)

The synthesis method is the same as that of 13a, except that oleic acid is used instead of stearic acid to obtain a white solid with a yield of 84%. ESI-MS: m/z [M ⁺ H]+380.2.

3) Synthesis of 2,5-dioxo-tetrahydropyrrole-1-linoleate (13c)

The synthesis method is the same as that of 13a, except that linoleic acid replaces stearic acid to obtain a white solid with a yield of 86%. ESI-MS: m/z [M+H] ⁺ 378.3.

(Project support: National Natural Science Foundation of China 30870553; National International Science and Technology Cooperation Project 2010DFA34370; Zhejiang Provincial International Science and Technology Cooperation Project 2013C14012.)

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention are included in the protection scope of the present invention. Inside.

Claims (2)

1. a kind of alpha-galactosylceramide isomers, it is characterised in that it changes into 4 in the configuration of sphingol chain, 5 is cis double With one or more cis-double bonds on key sphingol chain, acyl chain.

2. a kind of synthetic method of alpha-galactosylceramide isomers as claimed in claim 1, it is characterised in that including such as Lower step：

1）The structure of the cis sphingols of 4,5-:

Raw material is by the use of galactolipin as chiral source, and the first step first generates 4,6 hydroxyls that acetal protects galactolipin；Second step is carried out Oxidation, aldehyde radical is generated at 3 hydroxyls, removes the carbon of sugar 1,2；3rd step is reacted using Wittg, with pre-synthesis ten Four carbon phosphorus ylides react, and obtain 4,5- cis-form olefins；4th step original 5 hydroxyls on carbon carry out Azide, in this position And occur configuration needed for carbonoid upset is obtained；5th step takes off ketal reaction, obtains (2S, 3R, 4Z) -2- nitrine -1,3- glycol Derivative；

2）The synthesis of alpha-galactosylceramide isomers：

Saccharide donor is synthesized first, is synthesized from galactolipin after full TMS galactolipins, simple process, with obtaining TMS iodine after iodine reagent effect Sugar, is not post-processed, at once under catalyst action, and saccharide acceptor-sphingol reaction, obtains single alpha-glycosyl isomers；So The TMS gone down afterwards in gentle simple condition on galactolipin；Nitrine in the compound of acquisition is converted into amino, due to compound It is very active, it is directly thrown into next step；Last acid amides reaction is used first is derivatized to active ester carboxylic acid, then is reacted with amino, Obtain alpha-galactosylceramide isomers.