CN110016066B

CN110016066B - Synthesis method of I-type N-glycan antenna

Info

Publication number: CN110016066B
Application number: CN201910260284.0A
Authority: CN
Inventors: 孙建松; 陈健
Original assignee: Jiangxi Normal University
Current assignee: Jiangxi Normal University
Priority date: 2019-04-02
Filing date: 2019-04-02
Publication date: 2021-11-02
Anticipated expiration: 2039-04-02
Also published as: CN110016066A

Abstract

The invention discloses a method for synthesizing an I-type N-glycan antenna, which can be obtained from a monosaccharide block which is easy to obtain by linear synthesis with 7 steps at the longest by combining a 2-glycosylation method and an MPEP glycosylation scheme, and the total yield is 29%. The invention solves the problems of poor stereoselectivity and low yield of sialylglycosidation, prepares the I-type N-glycan antenna with high efficiency and high stereoselectivity, greatly shortens the synthetic route, provides possibility for mass synthesis, and greatly promotes the research on the activity mechanism of N-glycan compounds and the research on the structure-activity relationship thereof.

Description

Synthesis method of I-type N-glycan antenna

Technical Field

The invention belongs to the technical field of medicines, and particularly relates to a synthesis method of an I-type N-glycan antenna.

Background

N-glycan (asparagine-linked glycan) antennas are widely found in glycolipids and glycoproteins. Structurally, antennas can be divided into two classes, type I antennas, which contain alpha-2, 6 linked salivary residues, and type II antennas, which contain alpha-2, 3 linked salivary residues. Given the critical role of N-glycans in maintaining the normal function of glycoproteins and viral host recognition, chemical synthesis of N-glycans with well-defined chemical structures has become an area of extensive research in glycochemistry.

Sialic acid protected by Ac at position 5

Although N-glycan has a wide application prospect, people are prompted to research the N-glycan into the N-glycan, and the N-glycan antenna is the core of synthesizing N-glycan and is also a difficulty for synthesizing the N-glycan. The first step is to construct sialic acid alpha glycosidic linkages, and the subsequent step of efficiently extending sugar chains is a little more challenging. Many scientists have synthesized the synthesis, but the efficiency of the synthesis and the flexibility thereof are not satisfactory.

The group of Samuel J.Danishefsky, 2009, synthesized monomeric IgG containing type I N-glycan antennae. The synthesis of the group adopts chain synthesis from back to front, but each step of the synthesis needs to carry out protecting group operation on an acceptor, a virulent substance such as hydrazine hydrate is needed when the hydroxyl of the acceptor is exposed, and the yield is only 52 percent when CA is removed.

The Shang-Cheng Hung group used a one-pot method to synthesize the 3-saccharide type I N-glycan aerial in 2014. However, the yield of synthesized 3-sugar is 45% and the flexibility is poor, the Phth protecting group needs to be removed first under severe conditions when the elongation of terminal sialic acid is carried out, and the removal of OMe group at the anomeric position of sugar chain and the preparation of donor are also greatly limited if the elongation is needed.

In 2016, synthesis of N-glycans by Koichi Fukase group, 2+2 synthesis was performed on the antenna. When the sialic acid-containing 2 sugar module is constructed, the alpha selectivity is only 16:1, the yield is also only 85%, the yield operation is complicated when the 2 sugar module is changed into a donor, the yield is low, expensive Ir (cod) (PPh2Me)2] PF6 catalysis is needed, and the derivatization after synthesis is also very difficult.

There is therefore a great difficulty with the high efficiency and flexibility of type I N-glycan antennas. There is a strong need to establish an effective antenna assembly route to promote the synthesis of N-glycans and to perform subsequent study of structure-activity relationships.

Disclosure of Invention

The technical problem to be solved by the invention is to establish an effective I-type N-glycan antenna assembly route to promote the synthesis of N-glycan and the subsequent research on structure-activity relationship.

In order to solve the technical problems, the invention adopts the technical scheme that: a method for synthesizing an I-type N-glycan antenna comprises the following steps:

(1) dissolving a glycosyl donor compound 1 and a glycosyl acceptor compound 2 in a first solvent, adding a drying agent, adding NIS and TfOH, and carrying out glycosylation reaction to obtain a compound 3, wherein the molar ratio of the glycosyl donor compound 1 to the glycosyl acceptor compound 2 to the NIS to the TfOH is 1:1:1: 1-5: 1:5:5, the concentration of the compound 1 in the first solvent is 0.001-1 mol/L, and the first solvent is dichloromethane; the glycosidation reaction temperature is-40 ℃ to 0 ℃;

(2) dissolving a compound 3 in a second solvent, adding copper acetate at 45-50 ℃ for reaction to obtain a compound 4, wherein the second solvent is methanol, the molar ratio of the compound 3 to the copper acetate is 1: 1-1: 10, and the concentration of the compound 3 in the second solvent is 0.001-1 mol/L;

(3) dissolving a compound 4 in a third solvent, adding thioacetic acid at room temperature, and reacting to obtain a compound 5, wherein the molar ratio of the compound 4 to the thioacetic acid is 1: 10-1: 100, and the concentration of the compound 4 in the third solvent is 0.001-1 mol/L;

(4) compound 5, Ph₃P、Pd(PPh₃)₂Cl₂Dissolving CuI in a fourth solvent, cooling to-78-40 ℃, adding a solution of p-methoxyphenylacetylene in a fifth solvent, heating to 50-100 ℃, and reacting to obtain a compound 6, a compound 5 and Ph₃P、Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.2:0.1:0.2: 1.2-1: 0.5:0.2:0.5:1.6, and the concentration of the compound 5 in the fourth solvent is 0.01-1 mol/L;

(5) dissolving the compound 6 and the glycosyl acceptor compound 7 in a sixth solvent, adding a drying agent, and carrying out glycosylation reaction at-50-0 ℃ under the catalysis of Lewis acid and NIS to obtain a compound 8;

(6) compound 8, Ph₃P、Pd(PPh₃)₂Cl₂Dissolving CuI in a seventh solvent, cooling to-78-40 ℃, adding a solution of p-methoxyphenylacetylene in an eighth solvent, heating to 50-100 ℃, and reacting to obtain a compound 9; the compound 8, Ph₃P、Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.2:0.1:0.2: 1.2-1: 0.5:0.2:0.5:1.6, wherein the concentration of the compound 8 in the seventh solvent is 0.01-1 mol/L;

(7) dissolving the compound 9 and the glycosyl acceptor compound 10 in a ninth solvent, adding a drying agent, and reacting at-50-0 ℃ under the action of a catalyst to obtain a compound 11.

In the step (1), the glycosylation reaction temperature is preferably-40 ℃ to-20 ℃; the concentration of the compound 1 in the first solvent is preferably 0.001-0.003 mol/L, and the drying agent is selected from molecular sieves, preferably

Molecular sieves, more preferably

The molecular sieve is characterized in that the molar ratio of the glycosyl donor compound 1 to the glycosyl acceptor compound 2 to the NIS to the TfOH is preferably 1:1:1: 1-2: 1:5:5, and more preferably 2:1:5: 2-2: 1:5: 5.

The amount of TfOH used had a large effect on the glycosidation reaction of 1 and 2. When TfOH was used in catalytic amounts (0.2eq), only 9% of the glycosidation product 3 was isolated. The yield of glycosidated product 3 gradually rose from 34% to 90% as the amount of TfOH increased from 0.5eq to 1.0 eq. Surprisingly, good sialyl stereoselectivity (α/β ═ 25:1) was also maintained using equivalent amounts of TfOH. Further increase in the amount of TfOH to 5 equivalent yields and ratios did not change. To assess the effect of the diastereomer of the thiosialic acid donor on the sialylation results, donor 1 α was also glycosylated under the same conditions as 3. Although a slight decrease in yield and stereoselectivity was observed, they were still at a good level (83%,. alpha./. beta. ═ 20:1) (table 1).

TABLE 1 glycosylation condition optimization

In the step (2), the molar ratio of the compound 3 to the copper acetate is preferably 1: 1-1: 4, and the concentration of the compound 3 in the second solvent is preferably 0.02-0.004 mol/L.

The second solvent is one or more selected from methanol, DCM or acetone, preferably methanol.

When the second solvent is a mixed solvent of DCM and MeOH in a volume ratio of 1:1, the reaction yield of step 2 is 60%, and when the second solvent is a mixed solvent of acetone and methanol in a volume ratio of 1:1, the reaction yield of step 2 is 45%. When methanol is used as a reaction solvent, the reaction yield of the step 2 is 90%.

In the step (3), the third solvent is pyridine; the molar ratio of the compound 4 to the thioacetic acid is preferably 1: 10-1: 30, and the concentration of the compound 4 in the third solvent is preferably 0.001-0.6 mol/L.

We first tried the reductive acetylation of compound 4 with thioacetic acid using a mixture of dichloromethane and triethylamine, but the reaction was unsuccessful and we exchanged pyridine and dichloromethane for the solvent and reductively aminated thioacetic acid to get the desired product 5 in general yield. Finally we directly reductively aminated with thioacetic acid in pyridine as solvent to give the desired product 5 in 72% yield. Triethylamine and pyridine are both used to neutralize acids in the system to enhance the nucleophilicity of thioacetic acids.

In the step (4), the fourth and fifth organic solvents are the same or different and are selected from N, N-Dimethylformamide (DMF), diisopropylamine (i-Pr)₂NH), Tetrahydrofuran (THF), Dichloromethane (DCM), acetone, methanol (MeOH) or ethanol (EtOH), preferably, the fourth organic solvent is DMF and i-Pr₂NH, more preferably, the DMF and i-Pr₂The volume ratio of NH is 1: 3-5, the compound 5 can be better dissolved; preferably, the fifth organic solvent is DMF. The compound 5, Ph₃P、Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is preferably 1:0.2:0.1:0.2:1.2 to 1:0.45:0.1:0.45: 1.5; of compound 5 in a fourth organic solventThe concentration is preferably 0.01 to 0.03 mol/L.

In the step (5), the sixth organic solvent is one or more of toluene, dichloromethane, diethyl ether, acetone and THF, and dichloromethane is preferred. The Lewis acid is TMSOTf, and the molar ratio of the compound 7 to the Lewis acid to the NIS is 1:0.1: 1-1: 1: 2; preferably 1:0.3: 1.2-1: 0.5: 1.5; the molar ratio of the compound 6 to the compound 7 is 1: 1-1: 5, preferably 1: 1-1: 1.2; the mass-volume ratio of the glycosylation donor shown in the formula I to the sixth organic solvent is 20-100 mg/mL, preferably 20-50 mg/mL; the desiccant is selected from molecular sieves, preferably

Molecular sieves, more preferably

And (3) a molecular sieve.

In the step (6), the seventh and eighth organic solvents are the same or different and are selected from N, N-Dimethylformamide (DMF), diisopropylamine (i-Pr)₂NH), Tetrahydrofuran (THF), Dichloromethane (DCM), acetone, methanol (MeOH), or ethanol (EtOH). Preferably, the seventh organic solvent is DMF and iPr₂NH, more preferably, the DMF and i-Pr₂The volume ratio of NH is 1: 3-1: 5, compound 8 can be better dissolved; preferably, the eighth organic solvent is DMF. The compounds II, Ph₃P、Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.2:0.1:0.2: 1.2-1: 0.5:0.2:0.5: 1.6; preferably 1:0.2:0.1:0.2: 1.2-1: 0.45:0.1:0.45: 1.5; the concentration of the compound 8 in the seventh organic solvent is 0.01 to 1mol/L, preferably 0.01 to 0.03 mol/L.

In the step (7), the ninth organic solvent is one or more of toluene, dichloromethane, diethyl ether, acetone and THF, preferably dichloromethane; the Lewis acid is TMSOTf, and the molar ratio of the compound 9 to the Lewis acid to the NIS is 1:0.1: 1-1: 1: 2; preferably 1:0.3: 1.2-1: 0.5: 1.5; of compound 6 and compound 7The molar ratio is 1: 1-1: 5, preferably 1: 1-1: 1.2; the mass-volume ratio of the glycosylation donor shown in the formula I to the sixth organic solvent is 20-100 mg/mL, preferably 20-50 mg/mL; the desiccant is selected from molecular sieves, preferably

Molecular sieves, more preferably

And (3) a molecular sieve.

Preferably, any one of the steps (1) to (7) is carried out under the protection of inert gas, and the inert gas is selected from nitrogen, argon or helium.

The synthesis of type I antenna 11 starts with coupling between 1 and the primary hydroxyl acceptor 2, which acceptor 2 protects with IP at the end of the protection. Under the action of NIS/TfOH, in CH₂Cl₂The disaccharide sialidase 3 (90% and alpha-isomer) is obtained with high stereoselectivity and high efficiency by glycosylation reaction in solvent. In Cu (OAc)₂Under the action of (3), the participated group removal and the methyl esterification reaction of (3) both obtain better effects, so that the reaction is smoothly carried out to obtain 4 (90%). Thioacetic acid/pyridine to react N in 4₃Conversion to the corresponding acetamido group gave potential disaccharide donor compound 5 with isolation up to 72% followed by activation by Sonogashira reaction to give disaccharide MPEP donor compound 6 (87%). Donors 6 and 7 were efficiently glycosylated under standard activation conditions to give the trisaccharide potential donor compound 8, which was then converted to the trisaccharide MPEP donor 9 by Sonogashira reaction (83%). Subsequent glycan chain extension requires a trisaccharide MPEP donor and an inert upright bond OH of 10. Interestingly, no decrease in glycosylation efficiency was observed for glycosidation between 9 and 10, and a good 82% yield was obtained for the tetrasaccharide potential donor 11, which is a good basis for type I antenna installation. Thus, by combining the 2-glycosylation approach with the scheme of MPEP glycosylation, type I antenna 11 can be obtained from readily available monosaccharide blocks by a maximum of 7-step linear synthesis with an overall yield of 29%.

possible mechanism by which the pic group exerts its chirality controlThe following were used: the first is the pic-promoted triflated salivation mechanism (fig. 1, mechanism a) and the other is the pic participation mechanism (fig. 1, mechanism B). In the first mechanism, the equivalent amount of triflic acid used protonates the nitrogen atom of the pic group, resulting in the formation of a strongly electron-withdrawing pyridylmethyl salt, with the N at the C5 position₃The electron-withdrawing effect combines to generate unstable monooxynium under the effect of NIS/TfOH, thereby promoting the beta-attack of the triflate anion. Triflating to obtain sialic acid intermediate I. Then the triflated sialic acid intermediate and a receptor are subjected to Sn2 substitution to obtain the alpha-sialic acid derivative. In the second mechanism, the pic group is at C5-N even in the presence of a stoichiometric amount of trifluoromethanesulfonic acid₃Directly as a participating group, form the thermodynamically more stable 6-membered intermediate II through which subsequent Sn2 attack of the acceptor also leads to the α -selective glycosidation product.

Has the advantages that:

1) the invention solves the problems of poor stereoselectivity and low yield of sialylglycosidation.

2) The invention prepares the I-type N-glycan antenna with high efficiency and high stereoselectivity. The research on the activity mechanism of the N-glycan compound and the research on the structure-activity relationship of the N-glycan compound are greatly promoted.

3) The present invention utilizes a reliable sialylglycosylation approach and a potentially active "glycoside synthesis strategy characterized MPEP glycosylation protocol. Greatly shortens the synthesis route and provides possibility for mass synthesis.

Drawings

FIG. 1 is a mechanism for high stereoselectivity of glycosylation.

Detailed Description

The invention will be better understood from the following examples. However, those skilled in the art will readily appreciate that the description of the embodiments is only for illustrating the present invention and should not be taken as limiting the invention as detailed in the claims.

In the present invention, abbreviations have the following meanings:

PIC 2-picolyl (2-picoliyl), structural formula:

NIS N-iodo-succinimide (N-Iodosuccinimide)

IP：

MPEP

Phth Phthaloyl (Phthaloyl)

TfOH Trifluoromethanesulfonic acid (triflate)

TMSOTf Trimethylsilyl trifluoromethanesulfonate (Trimethylsilyl triflate)

Bz Benzoyl (Benzoyl)

Bn Benzyl (Benzyl)

Ac Acetyl group (Acetyl)

The product obtained by each step of reaction has high purity, and no impurity peak is seen in a 400-million nuclear magnetic resonance hydrogen spectrum.

The starting materials not mentioned in the present invention are all commercially available.

Synthesis of reaction raw materials:

1. sugars 1-1, 2-1, 7-1, 10-1, appropriately protected with groups, were synthesized according to methods conventional in the art.

2. Synthesis of Compound 1

Synthetic references for compound 1; yu, c. -s.; niikura, k.; lin, C. -C.; wong, C. -H.Angew. chem.Int.Ed.2001,40, 2900-:

dissolving Compound 1-1(100mg,0.17mmol) in pyridine (4.0mL), adding LiCl (22 mg,0.52mmol) at room temperature, heating the reaction system under reflux at 120 deg.C for 24 hr, concentrating under reduced pressure to remove pyridine, and collecting the residueDissolving the residue in dichloromethane, washing with 1mol/L HCl and saturated NaCl, drying with anhydrous sodium sulfate, filtering, and concentrating under reduced pressure to obtain crude product without further purification. The compound obtained above was dissolved in dry DMF (2mL) and PicBr. HBr (90mg,0.36mmol) and K were added at room temperature₂CO₃(95mg,0.69mmol) was stirred at room temperature for 5 hours under the protection of N2, TLC tracing showed the completion of the reaction of the starting material, the reaction system was extracted with dichloromethane and washed with 1mol/L HCl, saturated sodium bicarbonate and saturated NaCl in this order, and dried over anhydrous sodium sulfate. Filtration and concentration under reduced pressure gave a crude product which was finally subjected to column chromatography (PE: EA: DCM ═ 3:1:1) to give compound 1(90.6mg, 80% for 2steps) (α/β ═ 1:3).2 α: [ α ], (1: 3) as a white solid]_D ²⁵＝-22.5(c 1.0,CHCl3)；1H NMR(400MHz,CDCl3)δ8.58(d, J＝4.0Hz,1H),7.73(td,J＝1.6,7.6Hz,1H),7.38(t,J＝8.4Hz,3H),7.24(dd,J＝5.2,8.0 Hz,1H),7.13(d,J＝7.6Hz,2H),5.51(dd,J＝1.2,8.4Hz,1H),5.27-5.24(m,1H),5.24(d, J＝14.0Hz,1H),5.11(d,J＝13.6Hz,1H),5.06(ddd,J＝4.8,9.6,11.6Hz,1H),4.38(dd,J ＝2.4,12.4Hz,1H),4.32(dd,J＝4.0,12.8Hz,1H),3.86(dd,J＝1.6,10.4Hz,1H),3.21(t, J＝10.4Hz,1H),3.05(dd,J＝4.8,13.2Hz,1H),2.35(s,3H),2.20(s,3H),2.10(s,3H), 2.05(s,3H),1.91(s,3H),1.89(t,J＝12.4Hz,1H)；13C NMR(100MHz,CDCl3)δ170.8, 170.0,169.8,169.6,166.9,154.8,149.4,140.3,137.0,136.4,129.8,125.0,123.0,121.3,86.8, 73.4,71.7,69.1,68.2,67.6,61.7,60.2,37.7,21.4,21.0,20.9,20.8；HRMS(ESI)calcd for C30H34N4O11SNa[M+Na]+681.1837,found 681.1848.2β:[α]_D ²⁵＝-80(c 1.0,CHCl3)；1H NMR(400MHz,CDCl3)δ8.58-8.56(m,1H),7.72(td,J＝1.6,7.6Hz,1H),7.30-7.23(m,4 H),7.09(d,J＝7.6Hz,2H),5.63(dd,J＝2.0,5.6Hz,1H),5.48(ddd,J＝4.8,9.6,11.6Hz,1 H),5.21(d,J＝13.6Hz,1H),5.16-5.13(m,1H),5.14(d,J＝13.2Hz,1H),4.39(dd,J＝2.0, 10.4Hz,1H),4.38(dd,J＝2.4,12.4Hz,1H),4.26(dd,J＝6.0,12.4Hz,1H),3.34(t,J＝ 10.0Hz,1H),2.80(dd,J＝4.8,14.0Hz,1H),2.29(s,3H),2.16(s,3H),2.11(s,3H),2.08 (s,3H),2.021(s,3H),2.015(dd,J＝11.6,14.0Hz,1H)；13C NMR(100MHz,CDCl3)δ 170.4,170.1,169.8,169.6,166.9,155.0,149.2,140.2,136.9,136.0,130.1,125.2,123.0, 121.7,88.2,71.6,70.8(2C),69.2,67.7,61.7,60.3,36.5,21.3,21.0,20.9,20.8,20.7；HRMS (ESI)calcd for C30H35N4O11S[M+H]+659.2018,found 659.2049.

3. Synthesis method of compound 2

Ortho-iodophenol (803mg,3.65mmol) was first dissolved in CHCl₃To (7mL) was added weighed TBAB (522mg,1.6mmol) and K₂CO₃(15mL,0.25mmol/L) at 40 ℃ for 10 minutes, and then the peracetyl-protected galactobromoside, 2-1(1.0g,2.4mmol) of CHCl is added₃(7mL) the solution was stirred at the same temperature overnight, the reaction was monitored by spotting, and cooled to room temperature with copious amounts of DCM. First washed twice with water and then with saturated NaHCO₃Washing twice, combining organic phases and using anhydrous Na₂SO₄Drying, filtration and spin-drying of the filtrate on a chromatography column (PE: EA ═ 5:1) gave 2-2(937mg, 70%) as a white solid, [ alpha ], (r) ]]_D ²⁵＝-32.0(c 1.0,CHCl₃)；¹H NMR(400MHz, CDCl₃)δ7.80(dd,J＝1.6,7.6Hz,1H),7.32-7.28(m,1H),7.10(dd,J＝1.2,8.0Hz,1H), 6.85(td,J＝1.6,7.6Hz,1H),5.65(dd,J＝7.6,10.0Hz,1H),5.48(dd,J＝1.2,3.6Hz,1H), 5.13(dd,J＝3.2,10.4Hz,1H),5.04(d,8.0Hz,1H),4.29(dd,J＝6.8,11.2Hz,1H),4.19 (dd,J＝6.0,11.2Hz,1H),4.12-4.08(m,1H),2.20(s,3H),2.12(s,3H),2.08(s,3H),2.03 (s,3H)；¹³C NMR(100MHz,CDCl₃)δ170.4(2C),170.3,169.4,156.1,139.8,129.6,125.0, 116.0,100.3,86.9,71.3,71.0,68.2,66.9,61.5,21.5,20.8(2C),20.7；HRMS(ESI)calcd for C₂₁H₂₄IO₁₂[M+HCO₂]^-595.0307,found 595.0292.

Compound 2-2(800mg,1.45mmol) was dissolved in anhydrous methanol (6mL), and sodium methoxide (16mg, 0.29mmol) was added at room temperature under N₂Stirring the reaction system for 1h at the temperature under protection, monitoring the reaction completion by a point plate, adding methanol for dilution, adjusting the pH to about 7 by acid resin, filtering, and performing reduced pressure spin drying to obtain a crude product without further purification. The crude product was dissolved in acetonitrile (15mL) and CSA (67) was addedmg,0.29mmol) and PhCH (OMe)2(0.435ml,2.9mmol) at RT and N₂Under protection, the reaction system is heated to 60 ℃ for reaction overnight. The reaction was monitored by spotting plates, the system was cooled to room temperature and Et was added₃Quenching reaction by N, pouring into a mixed system of t ice water and petroleum ether (v/v is 1:1), stirring, filtering to obtain a white solid, washing with a small polar solvent, and drying to obtain a white solid compound 2-3(571.2mg, 84%) [ alpha ], (]_D ²⁵＝-23.7(c 0.3,CHCl₃)；¹H NMR(400MHz,CDCl₃) δ7.78(dd,J＝1.6,8.0Hz,1H),7.55-7.53(m,2H),7.41-7.38(m,3H),7.32(td,J＝1.6,8.4 Hz,1H),7.22(dd,J＝1.6,8.4Hz,1H),6.85(td,J＝1.6,7.6Hz,1H),5.61(s,1H),4.84(d, J＝8.0Hz,1H),4.44(dd,J＝1.6,12.8Hz,1H),4.32(d,J＝4.0Hz,1H),4.18-4.14(m,2 H),3.85(dd,J＝4.0,10.0Hz,1H),3.67(brs,1H),¹³C NMR(100MHz,CDCl₃)δ156.2, 139.3,137.4,129.8,129.5,128.4,126.6,125.1,117.0,103.3,101.7,88.0,75.1,72.3,71.7, 69.2,67.2；HRMS(ESI)calcd for C₁₉H₁₉IO₆Na[M+Na]⁺493.0119,found 493.0114.

Compound 2-3(280mg,0.6mmol) and dibutylselenium oxide (149.6mg,0.6mmol) were dissolved in toluene dried and concentrated under N at room temperature₂Heating to reflux under protection, reacting at the temperature for 3h, cooling to room temperature, and removing the solvent under reduced pressure to obtain a crude product. The crude product was dissolved in dry DMF (3mL) and CsF (93mg,0.61 mmol) and BnBr (80. mu.L, 0.67mmol) were added at room temperature under N₂Heating The reaction system to 80 ℃ under protection, stirring at The temperature overnight, cooling The reaction system to room temperature, adding dichloromethane for dilution, washing with water and saturated NaCl in sequence, and finally washing with anhydrous Na₂SO₄Drying, filtering and rotary drying under reduced pressure to obtain a crude product without further purification. Dissolving the crude product in pyridine 4ml, adding benzoyl chloride (0.5ml), stirring the reaction system at the temperature for 1h, monitoring the reaction completion by a dot plate, adding methanol to quench the reaction, and sequentially adding water, 1NHCl and saturated NaHCO₃Washing with saturated NaCl, washing with anhydrous Na₂SO₄Drying, filtering, spin-drying under reduced pressure, and purifying with chromatography column to obtain white solid 2-4(250mg, 63% for 3 steps): [ alpha ]]_D ²⁵＝+13.9(c 0.75,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.04(d,J＝7.6Hz,2 H),7.65(d,J＝8.0Hz,1H),7.59(dd,J＝7.2,16.4Hz,3H),7.43(t,J＝7.6Hz,2H), 7.37-7.32(m,4H),7.24-7.16(m,6H),6.73(t,J＝7.2Hz,1H),6.02(t,J＝9.2Hz,1H), 5.53(s,1H),5.08(d,J＝8.0Hz,1H),4.72(AB,2H),4.36(d,J＝12.4Hz,1H),4.31(d,J＝ 3.2Hz,1H),4.12(d,J＝12.4Hz,1H),3.83(dd,J＝3.2,10.4Hz,1H),3.54(brs,1H)；¹³C NMR(100MHz,CDCl₃)δ165.2,156.4,139.6,137.8,137.6,133.0,130.6,130.1,129.3, 129.1,128.4,128.3(2C),127.9,127.8,126.6,124.7,117.0,101.3,100.8,87.5,77.0,72.9, 71.1,70.0,69.1,67.1；HRMS(ESI)calcd for C₃₃H₂₉IO₇Na[M+Na]⁺687.0850,found 687.0862.

Dissolve compound 2-4(285mg,0.429mmol) in dry THF (3.0mL) and add 1N BH₃THF (2.15 mL,2.15mmol) and Cu (OTf)₂(31.2mg,0.086mmol) was placed under ice and protected by N2. Moving to room temperature again for reaction for 3 hours, monitoring the reaction by TLC, adding Et₃Quenching reaction with N using CH₂Cl₂Diluting, washing with water and saturated NaCl solution, drying with anhydrous sodium sulfate, filtering, concentrating under reduced pressure to obtain crude product, and performing column chromatography (PE: EA is 5:10 to obtain white solid compound 2(237.3mg, 83%) [ alpha ])]_D ²⁵＝+122.4(c 1.0,CHCl₃)；¹H NMR (400MHz,CDCl₃)δ7.43-7.29(m,10H),7.03(d,J＝8.8Hz,2H),6.85(d,J＝9.2Hz,2H), 5.45(d,J＝3.6Hz,1H),4.99(t,J＝10.8Hz,2H),4.92(d,J＝10.8Hz,1H),4.73(d,J＝11.2Hz,1H),4.25(dd,J＝8.8,10.4Hz,1H),3.92(dt,J＝2.8,10.0Hz,1H),3.80-3.72(m, 3H),3.77(s,3H),3.47(dd,J＝3.6,10.4Hz,1H)；¹³C NMR(100MHz,CDCl₃)δ155.6, 150.4,137.9(2C),128.7(2C),128.2(2C),128.1(2C),118.3,114.8,97.8,80.1,77.7,75.7, 75.3,72.2,63.5,61.5,55.8；HRMS(ESI)calcd for C₂₇H₂₉N₃O₆Na[M+Na]⁺514.1949,found 514.1957.

4. Synthetic reference for compound 7: hu, y.; yu, k.; shi, L. -L.; liu, l.; sui, J. -J.; liu, d. -y.; xiong, b.; sun, J. -S.J.Am.chem.Soc.2017,139,12736-12744 the specific experimental procedures are as follows:

compound 7-1(1.1g,1.7mmol) was dissolved in dry methanol (10mL) and NaOMe (9.18mg, 0.17mmol) was added under nitrogen at room temperature. Stirring at this temperature for 1h, and using acidic resin to adjust the system pH to about 7. Filtering, and removing the filtrate under reduced pressure to obtain a crude product without further purification. The crude product was dissolved in DMF (8 mL) and PhCH (OMe) was added₂(0.56mL,3.68mmol) and TsOH (56mg,0.29mmol) at room temperature under nitrogen. The system was stirred at this temperature overnight, the reaction was monitored by dot plate for completion, quenched with triethylamine, diluted with dichloromethane and successively with saturated NaHCO₃Washing with saturated NaCl and then with anhydrous Na₂SO₄And (5) drying. Filtering, removing the filtrate under reduced pressure, and purifying with chromatography column (PEEA 3:1) to obtain white solid compound 7-2(908.9mg, 88% for 2steps) (. alpha.)]_D ²⁵＝+42.3(c 1.0,CHCl₃)；¹H NMR(400MHz,Acetone-d6)δ7.86(s,4H),7.67(dd,J＝ 7.8,1.5Hz,1H),7.60–7.49(m,2H),7.44–7.28(m,5H),6.91–6.73(m,1H),5.97(d,J＝8.5Hz,1H),5.75(s,1H),4.65(t,J＝9.7Hz,1H),4.58–4.40(m,2H),4.00–3.89(m,2H), 3.88–3.78(m,1H).13C NMR(101MHz,Acetone-d6)δ157.07,140.19,138.95,135.32, 130.80,129.70,128.87,127.37,125.66,124.06,116.93,102.39,98.86,82.53,69.21, 69.06,67.93,58.02.；HRMS(ESI)calcd for C₂₇H₂₂INO₇Na[M+Na]⁺622.0333,found 622.0335.

Compound 7-2(500mg,0.83mmol) was dissolved in dry DMF (4 mL). NaH (66.8mg,1.67mmol) was added under an ice bath and nitrogen blanket. The reaction was stirred for 15min and BnBr (0.15mL,1.26 mmol) was added. The system was then warmed to room temperature, stirred at this temperature for 3 hours, spotted to monitor completion of the reaction, diluted with dichloromethane, and successively diluted with 1N HCl water, saturated NaHCO₃Washing with saturated NaCl, and washing with anhydrous Na₂SO₄Drying, filtering and removing the filtrate on a column. Column chromatography with (PE/EA ═ 10:1) afforded a white solid7-3(517.7mg,90％):[α]_D ²⁵＝ +101(c 0.5,CHCl₃)；¹H NMR(400MHz,Acetone-d6)δ7.83(d,J＝5.1Hz,4H),7.66–7.58 (m,3H),7.46–7.36(m,3H),7.36–7.26(m,2H),7.05–6.87(m,5H),6.77(td,J＝7.4,1.7 Hz,1H),5.94(d,J＝8.0Hz,1H),5.83(s,1H),4.83(d,J＝12.3Hz,1H),4.64–4.44(m,4H), 4.07–3.90(m,3H).¹³C NMR(101MHz,Acetone-d6)δ139.20,138.02,134.25,129.79, 128.74,128.04,127.90,127.74,127.30,126.18,124.74,123.16,115.97,101.05,97.84, 82.37,74.78,73.64,68.10,66.48,55.19.HRMS(ESI)calcd for C₃₄H₂₈INO₇Na[M+Na]⁺ 712.0803,found 712.0778.

Compound 7-3(460mg,0.67mmol) was dissolved in dry THF (7mL) and BH was added₃-NMe₃(200 mg,2.7mmol), cooling to 0 ℃ and adding AlCl₃(360mg,2.7mmol), the system is brought to room temperature, stirred at this temperature for 3h with CH₂Cl₂After dilution, pour into 1N H₂SO₄Stirring for 15min, organic phase using water and saturated NaHCO successively₃Saturated NaCl wash and anhydrous Na₂SO₄Drying. The filtrate was filtered and applied to a column (PE/EA ═ 3:1) to give 7(381.8mg, 81%) as a white solid, [ α ], []_D ²⁵＝+44.5(c 1.0,CHCl₃)；¹H NMR(400 MHz,CDCl₃)δ7.81(brs,1H),7.65(brs,3H),7.57(dd,J＝1.6,8.0Hz,1H),7.34-7.26(m, 5H),7.18-7.12(m,2H),7.09-7.06(m,2H),6.98-6.91(m,3H),6.70(ddd,J＝2.4,6.8,8.0 Hz,1H),5.72(d,J＝8.4Hz,1H),4.79(d,J＝12.0Hz,1H),4.66-4.53(m,4H),4.36(dd,J ＝8.4,10.8Hz,1H),3.93-3.80(m,4H)；¹³C NMR(100MHz,CDCl₃)δ156.1,139.2,138.1, 137.8,133.9,129.6,128.6,128.3,128.0,127.9,127.8,127.6,124.6,123.4,116.2,97.8,97.7, 86.8,78.8,74.7,74.6,73.8,73.5,70.3,55.1；HRMS(ESI)calcd for C₃₄H₃₀INO₇Na[M+Na]⁺ 714.0959,found 714.0964.

5. Synthetic reference Hu, y for compound 10; yu, k.; shi, L. -L.; liu, l.; sui, J. -J.; liu, d. -y.; xiong, b.; sun, J. -S.J.am.chem.Soc.2017,139,12736-12744. the specific reaction steps are as follows:

compound 10-1(190mg,0.34mmol) was selectively benzylated to give the intermediate crude product. The above intermediate compound was dissolved in dry DMF (2 mL). NaH (27.4mg,0.68 mmol) was added and the system stirred at this temperature for 15min at 0 ℃ under nitrogen, and AllBr (35.2. mu.L, 0.4mmol) was added. The system was then allowed to warm to room temperature and stirred for an additional 2 h. The reaction was monitored by spotting plates for completion, diluted with dichloromethane, and water, 1N HC, saturated NaHCO in sequence₃Washing with saturated NaCl, and washing with anhydrous Na₂SO₄Drying, filtering and removing the filtrate on a column. The column was filtered (PE/EA: 10:1) to give 10-2(193.4mg, 76% for 2steps) as a white solid, [ alpha ], []_D ²⁵＝+82.2(c 1.0,CHCl₃)；¹H NMR(400 MHz,CDCl₃)δ7.75(dd,J＝1.6,8.0Hz,1H),7.52-7.22(m,11H),7.04(dd,J＝1.2,8.0Hz, 1H),6.78(td,J＝1.6,7.6Hz,1H),6.02-5.92(m,1H),5.64(s,1H),5.52(d,J＝2.0Hz,1 H),5.36(dq,J＝1.6,17.2Hz,1H),5.25(dq,J＝1.2,10.0Hz,1H),4.96(d,J＝12.4Hz,1 H),4.81(d,J＝12.0Hz,1H),4.38-4.33(m,1H),4.30-4.27(m,2H),4.26-4.20(m,1H), 4.18-4.14(m,1H),4.00(t,J＝2.0Hz,1H),3.90-3.82(m,2H)；¹³C NMR(100MHz,CDCl₃) δ154.7,139.5,138.5,137.7,137.6,134.7,129.6,129.0,128.5,128.3,128.1,127.8,126.2, 124.3,118.2,114.9,101.6,98.0,87.4,78.9,76.6,75.4,73.5,73.4,68.6,65.4；HRMS(ESI) calcd for C₂₉H₃₀IO₆[M+H]⁺601.1082,found 601.1078.

Compound 10-2(150mg,0.25mmol) was dissolved in CH₂Cl₂(4ml), H was added₂O (1ml) and TFA (2ml) were at 0 ℃. The system is stirred and reacted for 1h at the temperature, diluted by dichloromethane and quenched by triethylamine. Sequentially using water and saturated NaHCO₃Saturated NaCl wash and anhydrous Na₂SO₄Drying. The crude product of the filtrate was filtered off and rotary dried without further purification. Subjecting the crude product to simple benzylation reaction to obtain white solid compound 10-3(142mg, 8)2％for 2steps):[α]_D ²⁵＝+36.5(c 0.5,CHCl₃)；¹H NMR(400MHz, CDCl₃)δ7.74(d,J＝1.6,8.0Hz,1H),7.46-7.44(m,2H),7.36-7.17(m,15H),6.77(td,J＝ 1.6,7.6Hz,1H),6.00-5.91(m,1H),5.55(d,J＝1.6Hz,1H),5.35(dq,J＝1.6,17.2Hz,1 H),5.23(dq,J＝1.2,10.4Hz,1H),4.93(d,J＝10.8Hz,1H),4.83(AB,2H),4.64(d,J＝ 12.0Hz,1H),4.53(d,J＝10.8Hz,1H),4.45(d,J＝12.0Hz,1H),4.28-4.18(m,3H),4.11 (t,J＝9.6Hz,1H),3.97(dd,J＝2.0,3.2Hz,1H),3.86(ddd,J＝2.0,4.4,9.6Hz,1H),3.79 (dd,J＝4.4,10.8Hz,1H),3.67(dd,J＝1.6,10.8Hz,1H)；¹³C NMR(100MHz,CDCl₃)δ 155.3,139.3,138.5,138.4,138.3,134.9,129.7,128.6,128.4,128.3(2C),128.0,127.9,127.7, 127.6,124.2,118.0,115.6,97.4(2C),87.5,79.4,75.2,74.9,74.6,73.3,72.9,72.7,72.4,69.0； HRMS(ESI)calcd for C₃₆H₃₇IO₆Na[M+Na]⁺715.1527,found 715.1534.

Compound 10-3(120mg,0.17mmol) was dissolved in DCM/MeOH (2mL, v/v ═ 1:1) mixed solvent, and PdCl was added₂(9.2mg,0.052mmol) at room temperature under nitrogen. The reaction was stirred at this temperature for 6h, the reaction was monitored by dot plate for completion, Et was used₃Quench the reaction with N, filter through celite and silica gel, spin off the filtrate, and pass through a column (PE/EA ═ 5:1) to give compound 10(90mg, 79%) as a colorless syrup, [ α ]]_D ²⁵＝+63.9(c 1.0, CHCl₃)；¹H NMR(400MHz,CDCl₃)δ7.74(dd,J＝1.6,7.6Hz,1H),7.43-7.16(m,17H), 6.77(td,J＝1.6,7.6Hz,1H),5.62(d,J＝1.6Hz,1H),4.87(d,J＝10.8Hz,1H),4.81(t,J ＝12.0Hz,2H),4.61(d,J＝12.0Hz,1H),4.55(d,J＝10.8Hz,1H),4.44(d,J＝12.0Hz,1 H),4.22-4.18(m,2H),4.04(dd,J＝8.4,10.0Hz,1H),3.87(ddd,J＝2.0,4.4,10.0Hz,1H), 3.77(dd,J＝4.4,10.8Hz,1H),3.63(dd,J＝2.0,10.8Hz,1H),2.59(brs,1H)；¹³C NMR (100MHz,CDCl₃)δ155.0,139.4,138.3,138.1,137.8,129.7,128.7,128.4,128.3,128.2, 128.0(2C),127.8,127.7,124.1,115.2,98.3,87.3,79.5,75.3,74.0,73.4,72.4,72.3,68.7, 68.5；HRMS(ESI)calcd for C₃₃H₃₃IO₆Na[M+Na]⁺675.1214,found 675.1221.

Example 1

(1) Synthesis of Compound 3

Compounds 1(60mg,0.092mmol) and 2(30.6mg,0.046mmol) were dissolved in dry CH₂Cl₂(1mL), activated 4A MS in N was added₂Under the protection of (1). After the reaction system was stirred at room temperature for 15 minutes, the reaction system was placed at-40 ℃ and stirred for 5 minutes, NIS (49.4mg,0.221mmol) and TfOH (8.0. mu.L, 0.092mmol) were added, the reaction was allowed to react at low temperature for 2 hours, TLC plates were used to monitor the completion of the reaction, Et was added₃And (3) quenching the reaction by N, filtering, washing by saturated sodium bicarbonate and saturated NaCl, and drying by anhydrous sodium sulfate. Filtration and concentration under reduced pressure gave a crude product which was finally subjected to column chromatography (PE: EA: DCM: 3:1:1) to give compound 3(49.7mg, 90%) as a white solid]_D ²⁵＝-3.0(c 0.9, CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.58(d,J＝4.8Hz,1H),8.05(dd,J＝1.2,8.4Hz,2 H),7.74(td,J＝1.2,7.6Hz,1H),7.64(dd,J＝1.6,7.6Hz,1H),7.58-7.53(m,1H), 7.44-7.13(m,16H),6.72(td,J＝1.2,7.2Hz,1H),6.05(dd,J＝8.0,10.0Hz,1H),5.51(dd, J＝1.6,9.2Hz,1H),5.46(d,J＝14.0Hz,1H),5.42-5.38(m,1H),5.23(d,J＝13.6Hz,1 H),5.11-5.00(m,3H),4.75(d,J＝11.6Hz,1H),4.70(d,J＝12.4Hz,1H),4.57(d,J＝12.4 Hz,1H),4.34(dd,J＝2.4,12.8Hz,1H),4.16(dd,J＝4.8,12.4Hz,1H),4.04-3.97(m,3H), 3.83-3.77(m,2H),3.73(dd,J＝5.6,10.0Hz,1H),3.27(t,J＝10.4Hz,1H),2.88(dd,J＝ 4.8,12.4Hz,1H),2.11(s,3H),2.09(s,3H),2.05(s,3H),2.00(s,3H),1.84(t,J＝12.4Hz, 1H)；¹³C NMR(100MHz,CDCl₃)δ170.8,169.9(2C),169.6,167.0,165.3,156.6,154.2, 149.2,139.4,138.4,137.7,137.5,132.9,130.7,130.0,129.4,128.5,128.4,128.3,127.8, 127.7,124.4,123.4,121.6,116.5,100.6,98.8,87.0,80.0,74.5,73.9,72.6,72.1,71.7,71.1, 68.0,67.9,67.4,63.8,62.2,60.1,37.4,21.1,21.0(2C),20.8(2C)；HRMS(ESI)calcd for C₅₆H₅₈IN₄O₁₈[M+H]⁺1201.2785,found 1201.2882.

(2) Deprotection of Compound 3 protecting groups

Compound 3(45.6mg,0.038mmol) was dissolved in anhydrous methanol (2mL) and Cu (OAc) was added₂(7.5mg,0.042 mmol.) the reaction was warmed to 45 ℃ and the system was stirred overnight with Et₃Quenching the reaction with N, concentrating under reduced pressure, and separating with chromatography column to obtain white solid (PE/EA is 2:1) and white syrup 39(38.4mg, 90%) [ alpha ], (]_D ²⁵＝+5.3(c 1.0, CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.04(dd,J＝1.2,8.0Hz,2H),7.65(dd,J＝1.6,7.6 Hz,1H),7.58-7.54(m,1H),7.44-7.40(m,4H),7.36-7.32(m,2H),7.13(m,8H),6.74(td, J＝1.6,7.6Hz,1H),6.05(dd,J＝8.0,10.0Hz,1H),5.51(dd,J＝1.6,9.2Hz,1H),5.43 (ddd,J＝2.4,4.8,9.6Hz,1H),5.08(d,J＝8.0Hz,1H),5.05(d,J＝11.6Hz,1H),4.87(ddd, J＝4.8,9.6,12.0Hz,1H),4.75(d,J＝11.2Hz,1H),4.70(d,J＝12.0Hz,1H),4.57(d,J＝ 12.4Hz,1H),4.35(dd,J＝2.4,12.8Hz,1H),4.16(dd,J＝5.2,12.8Hz,1H),4.04(d,J＝ 2.8Hz,1H),3.96(dd,J＝6.8,10.4Hz,1H),3.86-3.77(m,3H),3.74(s,3H),3.64(dd,J＝ 6.8,10.0Hz,1H),3.25(dd,J＝9.6,10.4Hz,1H),2.75(dd,J＝4.4,12.4Hz,1H),2.17(s,3 H),2.12(s,3H),2.09(s,3H),2.01(s,3H),1.79(t,J＝12.8Hz,1H)；¹³C NMR(100MHz, CDCl₃)δ170.9,169.9(2C),169.7,167.6,165.3,156.6,139.4,138.4,137.6,133.0,130.7, 130.1,129.4,128.5,128.4,128.2,127.8,127.7,124.4,116.6,100.6,98.8,87.1,80.0,74.5, 73.7,72.4,72.1,71.8,71.1,71.0,68.0,67.8,63.5,62.3,60.0,53.2,37.4,21.2,21.0,20.9,20.8； HRMS(ESI)calcd for C₅₁H₅₄IN₃O₁₈Na[M+Na]⁺1146.2339,found 1146.2359.

(3) Conversion of Compound 4 protecting group

Compound 4(39.3mg,0.035mmol) is dissolved in dry pyridinePyridine (0.6mL), thioacetic acid (0.6mL) was added at 0 ℃ and N₂The reaction system was stirred at room temperature for 24h under protection, dried under reduced pressure, and chromatographed on a column (PE/EA 1:3) to give compound 5(28.7mg, 72%) as a colorless liquid, [ α ], []_D ²⁵＝+7.0(c 0.5,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.05(dd,J＝1.2,8.4Hz,2H),7.64(dd,J＝1.6,8.0Hz,1H), 7.57-7.53(m,1H),7.45-7.40(m,4H),7.36-7.32(m,3H),7.29-7.13(m,7H),6.73(td,J＝ 1.6,7.6Hz,1H),6.04(dd,J＝8.0,10.0Hz,1H),5.45(ddd,J＝2.8,6.4,8.8Hz,1H), 5.32-5.29(m,2H),5.12(d,J＝8.0Hz,1H),5.05(d,J＝11.2Hz,1H),4.92(ddd,J＝4.4, 9.6,12.0Hz,1H),4.78-4.68(m,2H),4.57(d,J＝12.4Hz,1H),4.38(dd,J＝2.4,12.4Hz,1 H),4.17-4.06(m,3H),4.05(dd,J＝6.4,12.4Hz,1H),3.92-3.87(m,2H),3.84(dd,J＝2.8, 10.4Hz,1H),3.72(s,3H),3.71(dd,J＝1.6,11.6Hz,1H),2.64(dd,J＝4.8,13.2Hz,1H), 2.17(s,3H),2.10(s,3H),2.05(s,3H),2.00(t,J＝12.4Hz,1H),1.94(s,3H),1.89(s,3H)；¹³C NMR(100MHz,CDCl₃)δ171.1,170.9,170.5,170.4,170.1,168.2,165.4,156.6,139.3, 138.6,137.7,132.9,130.7,130.1,129.5,128.4,128.3,128.2,127.8,127.7,127.6,124.4, 116.6,100.6,99.3,87.0,80.1,74.6,73.5,72.8,72.3,72.1,71.2,69.0,68.5,67.5,63.2,62.9, 53.1(2C),49.4,38.0,23.3,21.2,21.0,20.9；HRMS(ESI)calcd for C₅₃H₅₈INO₁₉Na[M+Na]⁺ 1162.2540,found 1162.2574.

(4) Activation of the IP protecting group of Compound 5

Compound 5(38mg,0.033mmol), Ph₃P(3.8mg,0.014mmol),Pd(PPh₃)₂Cl₂(2.2mg, 0.003mmol), and CuI (2.8mg,0.015mmol) were dissolved in DMF (0.26mL) andⁱPr₂NH (0.87mL) in a mixed solvent, cooling to-78 ℃ under the protection of nitrogen, and ventilating by a vacuum diaphragm pump. After three repetitions of aeration, p-methoxyphenylacetylene (4. mu.L, 0.03mmol) dissolved in DMF (0.26mL) was added. The temperature is raised to 70 ℃ and then the reaction is carried out for 4h. Point plate monitoring reaction complete addition of NH₄The reaction was quenched with Cl, diluted with ethyl acetate, filtered over celite and silica gel, first with saturated NH₄After three Cl washes, the combined organic phases were washed twice with saturated NaCl. With anhydrous Na₂SO₄And (5) drying. Packing silica gel powder for filtration, spin-drying the filtrate and packing. Chromatography on a column (PE/EA: 1:3) afforded 6(33.2 mg, 87%) as a pale yellow solid, [ alpha ], []_D ²⁵＝-37.5(c 0.64,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ7.83(dd,J＝1.2, 8.0Hz,2H),7.69(dd,J＝7.2,12.0Hz,1H),7.57(t,J＝7.2Hz,1H),7.49-7.38(m,6H), 7.34-7.30(m,4H),7.27-7.12(m,6H),6.94(t,J＝7.6Hz,1H),6.83(d,J＝8.8Hz,2H), 6.09(dd,J＝8.0,10.0Hz,1H),5.47-5.38(m,2H),5.31(d,J＝8.4Hz,1H),5.25(d,J＝8.0 Hz,1H),5.05(d,J＝11.2Hz,1H),4.93(td,J＝4.4,11.2Hz,1H),4.74(d,J＝11.2Hz,1 H),4.70(d,J＝12.0Hz,1H),4.57(d,J＝12.0Hz,1H),4.40(dd,J＝1.6,12.4Hz,1H), 4.20-4.07(m,3H),4.05(dd,J＝6.8,12.4Hz,1H),3.98(t,J＝7.2Hz,1H),3.89-3.85(m,2 H),3.83(s,3H),3.76-3.69(m,1H),3.72(s,3H),2.64(dd,J＝4.4,13.2Hz,1H),2.17(s,3 H),2.11(s,3H),2.05(s,3H),2.01(t,J＝12.4Hz,1H),1.93(s,3H),1.89(s,3H)；¹³C NMR(100MHz,CDCl₃)δ171.0,170.8,170.5,170.3,170.0,168.2,165.2,159.4,157.7, 138.7,137.8,133.4,132.9,132.6,132.2,132.1,130.2,129.9,129.1,128.7,128.4,128.3, 128.1,128.0,127.7,127.6,127.5,122.0,115.9,115.2,114.2,113.6,99.8,99.4,93.9,83.6, 80.4,74.5,73.4,72.8,72.4,72.1,71.4,69.0,68.5,67.6,63.4,63.0,55.4,53.1,49.4,38.0,23.3, 21.2,21.0,20.9,20.8；HRMS(ESI)calcd for C₆₂H₆₅NO₂₀Na[M+Na]⁺1166.3992,found 1166.4021.

(5) Synthesis of Compound 8

Compounds 6(59.6mg,0.052mmol) and 7(72mg,0.104mmol) were dissolved in activated AW-300 MS dry dichloromethane (1mL) and stirred at room temperature under nitrogen for 30min. The temperature was reduced to-35 ℃ and NIS (15.6mg,0.078mmol) and TMSOTf (4.7. mu.L, 0.026mmol) were added.After 3.5h of reaction Et was added₃The reaction was quenched with N. The filtrate was filtered and spun down on a column and the column was filtered (PE/EA: 1:2) to give a white foamy glycosidation product 8(69.8 mg, 83%) [ alpha ], (ii)]_D ²⁵＝+26.3(c 0.5,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.04(dd,J＝1.2,8.4 Hz,2H),7.76-7.57(m,5H),7.52-7.44(m,3H),7.42-7.13(m,15H),7.05-7.00(m,4H), 6.86-6.82(m,3H),6.65-6.61(m,1H),5.70(dd,J＝7.6,10.0Hz,1H),5.57(d,J＝8.4Hz,1 H),5.34-5.32(m,3H),5.02(d,J＝11.2Hz,1H),4.94(d,J＝12.4Hz,1H),4.88-4.84(m,1 H),4.83(d,J＝8.0Hz,1H),4.69(dd,J＝4.8,12.4Hz,1H),4.55-4.44(m,4H),4.38(dd,J ＝8.0,10.8Hz,1H),4.29-4.25(m,2H),4.13-4.03(m,4H),4.01(dt,J＝2.8,12.4Hz,1H), 3.82(dd,J＝4.8,8.8Hz,1H),3.73-3.54(m,6H),3.61(s,3H),2.54(dd,J＝4.4,12.8Hz,1 H),2.13(s,3H),2.06(s,3H),2.04(s,3H),2.03(s,3H),1.92(t,J＝12.4Hz,1H),1.88(s, 3H)；¹³C NMR(100MHz,CDCl₃)δ171.0,170.8,170.5,170.2,170.0,167.9,165.2,156.1, 139.1,138.9,138.8,138.4,137.8,133.8,133.3,130.1,130.0,129.6,128.6,128.4,128.2(2C), 128.0,127.8,127.7(2C),127.6,127.5,127.3,127.0,124.5,123.3,116.2,101.1,99.2,97.6, 86.8,80.0,78.1,75.0,74.9,74.3,73.2,73.0,72.8,72.3,71.6,69.2,68.9,68.4,67.6,62.9,62.5, 55.4,53.0,49.5,37.6,23.3,21.2,21.0,20.9(2C)；HRMS(ESI)calcd for C₈₁H₈₃IN₂O₂₅Na [M+Na]⁺1633.4222,found 1633.4260.

(6) Activation of the IP protecting group of Compound 8

The experimental procedure was the same as for the synthesis of Compound 6, giving a pale yellow solid compound 9(25mg, 83%) [ alpha ]]_D ²⁵＝-28.7 (c 0.5,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.04(dd,J＝1.2,8.4Hz,2H),7.62-7.58(m,1 H),7.48(dd,J＝7.2,8.0Hz,3H),7.37(dd,J＝1.6,8.0Hz,3H),7.30-7.13(m,18H), 7.03-6.98(m,4H),6.87-6.79(m,6H),5.70(dd,J＝7.6,10.0Hz,1H),5.65(d,J＝8.4Hz,1 H),5.32-5.25(m,3H),5.02(d,J＝11.6Hz,1H),4.93(d,J＝12.4Hz,1H),4.87-4.81(m,2 H),4.69(d,J＝12.4Hz,1H),4.67(d,J＝11.6Hz,1H),4.53-4.48(m,4H),4.39(dd,J＝8.4, 10.8Hz,1H),4.29-4.24(m,2H),4.12-4.02(m,4H),4.00-3.95(m,1H),3.85(s,3H),3.80 (dd,J＝4.8,8.4Hz,1H),3.72-3.53(m,6H),3.60(s,3H),2.53(dd,J＝4.4,12.8Hz,1H), 2.13(s,3H),2.06(s,3H),2.033(s,3H),2.030(s,3H),1.92(t,J＝13.6Hz,1H),1.88(s,3 H)；¹³C NMR(100MHz,CDCl₃)δ171.1,170.8,170.4,170.2,170.0,167.9,165.2,159.4, 157.3,139.0,138.9,138.5,137.8,133.3(2C),133.0,131.5,130.1,130.0,129.2,128.6,128.4 (2C),128.2,128.1,127.9,127.8,127.7,127.6(2C),127.5,127.3,126.9,123.1,122.3,115.7, 115.2,114.0,113.7,101.1,99.2,97.0,93.3,83.5,80.0,78.2,77.7,75.1,74.8,74.3,73.2,73.0, 72.8,72.3,71.6,69.2,68.8,68.3,67.6,62.8,62.4,55.4,53.0,49.5,37.5,23.3,21.2,21.0(2 C),20.9；HRMS(ESI)calcd for C₉₀H₉₀N₂O₂₆K[M+K]⁺1653.5413,found 1653.5417.

(7) Synthesis of Compound 11

Experimental procedure the synthesis of reference Compound 8 gave white foamy glycosidation product 11(32mg, 82%) [ alpha ]]_D ²⁵＝ +27.5(c 0.5,CHCl₃)；¹H NMR(400MHz,CDCl₃)δ8.00(d,J＝7.6Hz,2H),7.66-7.56(m, 4H),7.50-7.43(m,4H),7.36-7.31(m,5H),7.24-7.06(m,24H),7.03-6.95(m,4H), 6.85-6.80(m,3H),6.70-6.65(m,2H),5.68(dd,J＝8.0,10.4Hz,1H),5.35-5.30(m,2H), 5.22(dd,J＝2.8,5.6Hz,1H),5.13(d,J＝2.0Hz,1H),5.01(d,J＝11.6Hz,1H),4.89-4.75 (m,8H),4.68(d,J＝3.2Hz,1H),4.65(d,J＝2.4Hz,1H),4.55-4.67(m,4H),4.37(d,J＝ 10.8Hz,1H),4.28-4.19(m,4H),4.12-3.97(m,6H),3.87-3.83(m,3H),3.69-3.50(m,7H), 3.56(s,3H),3.31(d,J＝10.8Hz,1H),2.92(dd,J＝5.6,11.2Hz,1H),2.54(dd,J＝4.8, 12.8Hz,1H),2.13(s,3H),2.06(s,3H),2.03(s,3H),2.02(s,3H),1.92(t,J＝12.0Hz,1 H),1.88(s,3H)；¹³C NMR(100MHz,CDCl₃)δ171.1,170.9,170.5,170.2,170.1,167.9, 165.2,154.9,139.2,138.9,138.8,138.5,138.4,138.1,137.8,133.6,133.3,131.8,130.0(2C), 129.4,128.6,128.5(2C),128.4(2C),128.3(2C),128.2(2C),128.1,128.0,127.8,127.7, 127.6(2C),127.4(2C),127.3,127.0,124.0,123.2,123.0,114.8,101.0,99.1,97.0,95.8, 87.2,80.0,78.2,77.7,75.0,74.9,74.8,74.4,74.2,73.4(2C),73.0,72.8,72.7,72.6(2C), 72.4,71.6,70.7,69.7,69.1,69.0,68.8,67.6,62.9,62.4,55.7,53.0,49.4,37.5,23.3,21.2,21.0 (2C),20.9；HRMS(ESI)calcd for C₁₀₈H₁₁₂IN₂O₃₀[M+H]⁺2044.6373,found 2044.6370.

Example 2

(1) Reaction reference example 1 procedure and parameters of step (1) except that the molar ratio of glycosyl donor compound 1, glycosyl acceptor compound 2, NIS and TfOH was 2:1:5:5, the concentration of said compound 1 in the first solvent was 0.003 mol/L; the glycosidation reaction temperature is-20 ℃; the all alpha configuration yield is 87%

(2) The reaction was conducted in accordance with the procedure and parameters of step (2) in example 1, except that the molar ratio of Compound 3 to copper acetate was 1:4, the concentration of Compound 3 in the second solvent was preferably 0.004mol/L, the solvents were methanol and methylene chloride, the temperature was 50 ℃ and the yield was 60%

(3) The reaction is referred to the procedure and parameters of step (3) in example 1, except that the molar ratio of the compound 4 to thioacetic acid is preferably 1:10, and dichloromethane and pyridine in a volume ratio of 1:1 are used as solvents. The concentration of the compound 4 in the solvent was 0.001, yield 60%.

(4) The reaction is referred to the procedure and parameters of step (4) in example 1, except that said compound 5, Ph₃P、 Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.5:0.2:0.5:1.6, the concentration of compound 5 in the fourth solvent is 0.01, and the yield is 70%.

(5) Reaction reference the procedure and parameters of step (5) in example 1, except that the molar ratio of compound 7 to lewis acid, NIS is 1:0.5: 1.5; the molar ratio of the compound 6 to the compound 7 is 1: 1; the mass-volume ratio of the glycosylation donor to the sixth organic solvent is 20 mg/mL; the yield was 70%.

(6) Reference is made to the procedure and parameters of step (6) in example 1, except that said compound 8, Ph₃P、 Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.45:0.1:0.45: 1.5; the concentration of the compound 8 in the seventh organic solvent was 0.1mol/L, yield 60%.

(7) Reaction reference the procedure and parameters of step (7) in example 1, except that the molar ratio of compound 9 to lewis acid, NIS is 1:0.5: 1.5; the molar ratio of compound 9 to compound 10 is 1: 1; the mass-volume ratio of the glycosylation donor shown in the formula I to the sixth organic solvent is 20 mg/mL; the yield was 65%.

Comparative example 1: in step (1), compounds 1(60mg,0.092mmol) and 2(30.6mg,0.046mmol) were dissolved in dry CH₂Cl₂(1mL), activated 4A MS in N was added₂Under the protection of (1). After the reaction system was stirred at room temperature for 15 minutes, the reaction system was placed at-40 ℃ and stirred for 5 minutes, NIS (49.4mg,0.221mmol) and TfOH (1.6. mu.L, 0.0184mmol) were added, the reaction was allowed to react at low temperature for 2 hours, TLC plates were used to monitor the completion of the reaction, Et was added₃And (3) quenching the reaction by N, filtering, washing by saturated sodium bicarbonate and saturated NaCl, and drying by anhydrous sodium sulfate. Filtered and concentrated under reduced pressure to give the crude product, which is chromatographed (PE: EA: DCM ═ 3:1:1) to give compound 3(5mg, 9%)

Comparative example 2: in step (2), Compound 3(45.6mg,0.038mmol) was dissolved in anhydrous methanol (0.5mL) and dichloromethane (1.5mL), Cu (OAc) was added₂(7.5mg,0.042 mmol.) the reaction was warmed to 45 ℃ and the system was stirred overnight with Et₃Quench the reaction with N, concentrate under reduced pressure, and column chromatographe to give a white solid (PE/EA ═ 2:1) as a white syrup 4(25.6mg, 60%):

comparative example 3: in step (3), Compound 4(39.3mg,0.035mmol) was dissolved in dry pyridine (0.3mL) and dichloromethane (1mL), thioacetic acid (0.6mL) was added at 0 ℃ and N₂The reaction was stirred at room temperature for 24h under protection, dried under reduced pressure, and chromatographed (PE/EA ═ 1:3) to give compound 5(23.9mg, 60%) as a colorless liquid.

Claims

1. A method for synthesizing an I-type N-glycan antenna is characterized by comprising the following steps:

(2) dissolving a compound 3 in a second solvent, and adding copper acetate at 45-50 ℃ for reaction to obtain a compound 4, wherein the molar ratio of the compound 3 to the copper acetate is 1: 1-1: 10, and the concentration of the compound 3 in the second solvent is 0.001-1 mol/L; the second solvent is methanol;

(3) dissolving a compound 4 in a third solvent, adding thioacetic acid at room temperature, and reacting to obtain a compound 5, wherein the molar ratio of the compound 4 to the thioacetic acid is 1: 10-1: 100, and the concentration of the compound 4 in the third solvent is 0.001-1 mol/L; the third solvent is pyridine;

(5) dissolving a compound 6 and a glycosyl acceptor compound 7 in a sixth solvent, adding a drying agent, and carrying out glycosylation reaction at-50-0 ℃ under the catalysis of Lewis acid and NIS to obtain a compound 8, wherein the Lewis acid is TMSOTf;

(6) compound 8, Ph₃P、Pd(PPh₃)₂Cl₂Dissolving CuI in a seventh solvent, cooling to-78-40 ℃, adding a solution of p-methoxyphenylacetylene in an eighth solvent, heating to 50-100 ℃, and reacting to obtain a compound 9; the compound 8, Ph₃P、Pd(PPh₃)₂Cl₂The molar ratio of CuI to p-methoxyphenylacetylene is 1:0.2:0.1:0.2: 1.2-1: 0.5:0.2:0.5:1.6, and the concentration of the compound 8 in the seventh solvent is 0.01-1 mol/L;

(7) dissolving a compound 9 and a glycosyl acceptor compound 10 in a ninth solvent, adding a drying agent, and reacting at-50-0 ℃ under the action of a catalyst to obtain a compound 11, wherein the catalyst is Lewis acid and NIS, and the Lewis acid is TMSOTf;

wherein PIC is

IP is

MPEP is

2. The method for synthesizing the type I N-glycan antenna according to claim 1, wherein in the step (1), the glycosylation reaction temperature is-10 ℃ to-20 ℃; the concentration of the compound 1 in the first solvent is 0.001-0.003 mol/L, and the drying agent is

And (3) a molecular sieve.

3. The method for synthesizing the type I N-glycan antenna according to claim 1, wherein in the step (2), the molar ratio of the compound 3 to the copper acetate is 1: 1-1: 4, and the concentration of the compound 3 in the second solvent is 0.001-0.004 mol/L.

4. The method for synthesizing an N-glycan I antenna as claimed in claim 1, wherein in step (3), the third solvent is pyridine.

5. The method for synthesizing N-glycan I antennade according to claim 1, wherein in step (4), the fourth and fifth solvents are the same or different and are selected from one or more of N, N-dimethylformamide, diisopropylamine, tetrahydrofuran, dichloromethane, acetone, methanol or ethanol.

6. The method of claim 5, wherein the fourth solvent is DMF and I-Pr₂A mixed solution of NH, and the fifth solvent is DMF.

7. The method for synthesizing the type I N-glycan antenna as claimed in claim 1, wherein in the step (5), the sixth solvent is one or more of toluene, dichloromethane, diethyl ether, acetone and THF, and the molar ratio of the compound 7 to the Lewis acid and the NIS is 1:0.1: 1-1: 1: 2; the mol ratio of the compound 6 to the compound 7 is 1: 1-1: 5, the mass-to-volume ratio of the compound 6 to the sixth solvent is 20-100 mg/mL, and the drying agent is selected from molecular sieves.

8. The method for synthesizing type I N-glycan antenna of claim 1, wherein in step (6), the seventh and eighth solvents are the same or different and are selected from one or more of N, N-dimethylformamide, diisopropylamine, tetrahydrofuran, dichloromethane, acetone, methanol or ethanol.

9. The method of claim 8, wherein the seventh solvent is DMF and I-Pr₂Mixed solution of NH, DMF and i-Pr in the mixed solution₂NH volume ratio of 1: 3-5, wherein the eighth solvent is DMF.

10. The method for synthesizing the type I N-glycan antenna as claimed in claim 1, wherein in the step (7), the ninth solvent is one or more of toluene, dichloromethane, diethyl ether, acetone and THF, and the molar ratio of the compound 9 to the Lewis acid and the NIS is 1:0.1: 1-1: 1: 2; the molar ratio of the compound 9 to the compound 10 is 1: 1-1: and 5, the mass-volume ratio of the compound 9 to the ninth solvent is 20-100 mg/mL, and the drying agent is selected from molecular sieves.