[O:1]1[CH2:5][C@@H:4]([OH:6])[C@H:3]2[O:7][CH2:8][C@@H:9]([OH:10])[C@@H:2]12.N12CCCN=C1CCCCC2.[Cl:22][C:23]1[CH:24]=[C:25]2[N:32]=[C:31](S(C)(=O)=O)[N:30]([CH2:37][O:38][CH2:39][CH2:40][Si:41]([CH3:44])([CH3:43])[CH3:42])[C:26]2=[N:27][C:28]=1[I:29]>CN(C)C=O>[Cl:22][C:23]1[CH:24]=[C:25]2[N:32]=[C:31]([O:6][C@H:4]3[C@H:3]4[O:7][CH2:8][C@@H:9]([OH:10])[C@H:2]4[O:1][CH2:5]3)[N:30]([CH2:37][O:38][CH2:39][CH2:40][Si:41]([CH3:44])([CH3:43])[CH3:42])[C:26]2=[N:27][C:28]=1[I:29](3R,3aR,6R,6aR)-Hexahydrofuro[3,2-b]furan-3,6-diol (1.84 g) is dissolved in N,N-dimethylformamide (10 mL) and treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU; 1.9 mL). A solution of 6-chloro-5-iodo-2-(methylsulfonyl)-3-(2-trimethylsilanyl-ethoxymethyl)-3H-imidazo[4,5-b]pyridine (2.05 g) in N,N-dimethylformamide (20 mL) is added dropwise and the mixture is stirred for 2 hours at room temperature. The mixture is partitioned between water and ethylacetate and the organic phase is washed with brine and dried (MgSO4). The solvents are evaporated in vacuo and the residue is chromatographed on silica gel (cyclohexane/ethyl acetate 80:20→0:100) to give the title compound. LC (method 1): tR=1.17 min; Mass spectrum (ESI+): m/z=554 [M+H]+.
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