Reaction SMILES: CN(C)S([N:6]1[CH:10]=[CH:9][N:8]=[CH:7]1)(=O)=O.C([Li])CCC.[NH2:17][C:18]1[C:19]2[C:26](I)=[CH:25][N:24]([C@@H:28]3[O:48][C@H:47]([CH2:49][O:50][Si](C(C)(C)C)(C)C)[C@@H:38]([O:39][Si](C(C)(C)C)(C)C)[C@H:29]3[O:30][Si](C(C)(C)C)(C)C)[C:20]=2[N:21]=[CH:22][N:23]=1.N1C=CN=C1>C1COCC1.CCOC(C)=O.Cl.[Cl-].[Cl-].[Zn+2].C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CO>[NH2:17][C:18]1[C:19]2[C:26]([C:7]3[NH:6][CH:10]=[CH:9][N:8]=3)=[CH:25][N:24]([C@@H:28]3[O:48][C@H:47]([CH2:49][OH:50])[C@@H:38]([OH:39])[C@H:29]3[OH:30])[C:20]=2[N:21]=[CH:22][N:23]=1
Reactant: CC(C)(C)[Si](C)(C)OC[C@H]1O[C@@H](n2cc(I)c3c(N)ncnc32)[C@H](O[Si](C)(C)C(C)(C)C)[C@@H]1O[Si](C)(C)C(C)(C)C
Reactant: CN(C)S(=O)(=O)n1ccnc1
Agent: c1ccc([P](c2ccccc2)(c2ccccc2)[Pd]([P](c2ccccc2)(c2ccccc2)c2ccccc2)([P](c2ccccc2)(c2ccccc2)c2ccccc2)[P](c2ccccc2)(c2ccccc2)c2ccccc2)cc1
Agent: Cl
Agent: [Cl-]
Solvent: CCOC(C)=O
Solvent: CO
Solvent: C1CCOC1
Product: Nc1ncnc2c1c(-c1ncc[nH]1)cn2[C@@H]1O[C@H](CO)[C@@H](O)[C@H]1O
Temperature: 25 °C
Reaction time: 24 h
Yield: 13 %

Procedure:
To a stirred solution of 1-(N,N-dimethylsulfamoyl)-1H-imidazole (875 mg, 5 mmol) in THF (15 ml) was dropwise added n-butyllithium (1.6 M in hexane, 3.1 ml, 5 mmol) at −78° C. during 30 min. Then a solution of ZnCl2 (1M in THF, 10 ml, 10 mmol) was dropwise added at −78° C. and the mixture was warmed to RT during 45 min. Resulting orange solution was transferred to an argon purged mixture of 2′,3′,5′-tri-O-TBS-7-iodotubericidine {compound 4 from Example 17, Step 1} (735 mg, 1 mmol) and Pd(PPh3)4 (116 mg, 0.1 mmol) and the mixture was stirred at 90° C. for 24 h. The mixture was diluted with AcOEt (50 ml) and washed with aq EDTA (sat., 25 ml). Aqueous layer was re-extracted with AcOEt (10 ml). Collected organic extracts were dried over MgSO4, evaporated and the residue was chromatographed on silica (hexanes/AcOEt, 5:1 →1:1; then AcOEt) affording product in a mixture with unseparable starting protected imidazole. This mixture was directly deprotected by stirring in aq HCl (1M, 2 ml) and MeOH (2 ml) at 100° C. for 24 h. Volatiles were removed in vacuo and the rest was co-evaporated with water (5×). The residue was treated with MeOH and undissolved solid (imidazole) was filtered off and washed with MeOH. Filtrate was evaporated and reverse phase chromatography (0-4100% MeOH in water) afforded crude product, which was yet re-purified by column chromatography on silica (8% MeOH in CHCl3) providing title compound 2s as yellowish foam (42 mg, 13%). Compound was recrystallized from MeOH/water. Mp 153-156° C. [α]D −72.1 (c 0.19, DMSO). 1H NMR (499.8 MHz, DMSO-d6): 3.56 (ddd, 1H, Jgem=11.9, J5′b,OH=6.5, =4.6, H-5′b); 3.64 (dd, 1H, Jgem=11.9, J5′a,OH=5.0, J5′a,4′=4.1, H-5′a); 3.92 (ddd, 1H, J4′,5′=4.6, 4.1, J4′,3′=3.4, H-4); 4.10 (ddd, 1H, J3′,OH=5.2, J3′,2′=5.0, J3′,4′=3.4, H-3′); 4.36 (ddd, 1H, J2′,OH 6.3, J2′,1′6.0, J2′,3′=5.0, H-2′); 5.16 (dd, 1H, JOH,5′=6.5, 5.0, OH-5′); 5.17 (d, 1H, JOH,3′=5.2, OH-3′); 5.39 (d, 1H, JOH,2′=6.3, OH-5′); 6.05 (d, 1H, J1′,2′=6.0, H-1′); 7.00 (t, 1H, J4,5=J4,NH=1.4, H-4-imidazole); 7.22 (dd, 1H, J5,NH=2.0, J5,4=1.4, H-5-imidazole); 7.24 (bs, 1H, NHaHb); 7.86 (s, 1H, H-6); 8.06 (s, 1H, H-2); 10.23 (bs, 1H, NHaHb); 12.42 (bs, 1H, NH-imidazole). 13C NMR (125.7 MHz, DMSO-d6): δ2.25 (CH2-5′); 70.90 (CH-3′); 73.99 (CH-2′); 85.27 (CH-4′); 87.33 (CH-1′); 100.12 (C-4a); 107.87 (C-5); 116.81 (CH-5-imidazole); 119.44 (CH-6); 127.22 (CH-4-imidazole); 142.49 (C-2-imidazole); 150.82 (C-7a); 152.91 (CH-2); 158.58 (C-4). MS (ESI) m/z 333 (M+H), 355 (M+Na). HRMS (ESI) for C14H17N6O4 [M+H] calcd: 333.1306. found: 333.1306. Anal. Calcd for C14H16N6O4.1.85H2O.0.55CH3OH: C, 45.60; 1-1, 5.76; N, 21.93. Found: C, 45.67; H, 5.66; N, 21.86.