[CH:1]([C:4]1[CH:9]=[CH:8][C:7]([S:10]([NH:13][C:14](=[O:39])[CH:15]([C:30]2[CH:35]=[CH:34][C:33]3[O:36][CH2:37][O:38][C:32]=3[CH:31]=2)[O:16][C:17]2[CH:22]=[CH:21][C:20]([C:23]([O:25][CH3:26])=[O:24])=[CH:19][C:18]=2[CH2:27][CH2:28][CH3:29])(=[O:12])=[O:11])=[CH:6][CH:5]=1)([CH3:3])[CH3:2].[CH3:40][Si]([NH-])(C)C.C[Si]([NH-])(C)C.[Li+].[Li+].IC>C1COCC1>[CH:1]([C:4]1[CH:5]=[CH:6][C:7]([S:10]([NH:13][C:14](=[O:39])[C:15]([C:30]2[CH:35]=[CH:34][C:33]3[O:36][CH2:37][O:38][C:32]=3[CH:31]=2)([O:16][C:17]2[CH:22]=[CH:21][C:20]([C:23]([O:25][CH3:26])=[O:24])=[CH:19][C:18]=2[CH2:27][CH2:28][CH3:29])[CH3:40])(=[O:12])=[O:11])=[CH:8][CH:9]=1)([CH3:2])[CH3:3]To a solution of 0.516 g (0.93 mmol) of the product of Example 57 dissolved in 1.0 mL of anhydrous THF was added 2.80 mL (2.80 mmol) of a 1.0 M solution of lithium bis(trimethylsilylamide) in THF at -78° C. under a nitrogen atmosphere. The reaction mixture was magnetically stirred at -78° C. for 1 hour, then 174 μL (2.80 mmol) of iodomethane was added via syringe. The reaction was allowed to warm to room temperature and was stirred an additional 14 hours. The reaction was next quenched with excess 10% aqueous NaHSO4 and partitioned between EtOAc and water. The organic layer was washed with saturated aqueous NaCl, dried (MgSO4), filtered and evaporated. The residue was purified on a silica gel flash chromatography column eluted with CHCl3 --MeOH--NH4OH (90:10:1). Evaporation of the purified fractions and drying in vacuo afforded 0.293 g (55%) of the title compound as an amorphous solid.
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