C([Li])(CC)C.[F:6][C:7]1[CH:12]=[CH:11][N:10]=[C:9]2[N:13]([Si:16]([CH:23]([CH3:25])[CH3:24])([CH:20]([CH3:22])[CH3:21])[CH:17]([CH3:19])[CH3:18])[CH:14]=[CH:15][C:8]=12.CC1(C)[C@]23C4(ON4S(=O)(=[O:34])C2)C[C@H]1CC3.[Cl-].[NH4+]>C1COCC1>[F:6][C:7]1[C:12]([OH:34])=[CH:11][N:10]=[C:9]2[N:13]([Si:16]([CH:20]([CH3:22])[CH3:21])([CH:23]([CH3:25])[CH3:24])[CH:17]([CH3:18])[CH3:19])[CH:14]=[CH:15][C:8]=12sec-Butyl lithium (8.06 mL, 11.3 mmol, 1.4 M in cyclohexane) was added dropwise to 4-fluoro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridine (1.5 g, 5.13 mmol, prepared as described in L′Heureux, et al., Org. Lett., 5(26) p. 5023 (2003)) in THF (100 mL) at −78° C. The reaction was stirred for 30 minutes. (1R)-(−)-(10-camphorsulfonyl)oxaziridine (2.94 g, 12.8 mmol) in THF (10 mL) was added rapidly, and the reaction was stirred at −78° C. for 30 minutes. A solution of saturated ammonium chloride (50 mL) was added, and the reaction mixture was allowed to reach room temperature. After one hour, the aqueous phase was extracted with AcOEt, dried over MgSO4 and concentrated to a solid, which was triturated in ether. The solid (most of the camphor side product) was filtered off, and the filtrate concentrated and purified by chromatography (25M, toluene/AcOEt 95/5) to yield a paste. The paste was triturated with hexanes, and the filtrate was concentrated to dryness to yield 4-fluoro-1-(triisopropylsilyl)-1H-pyrrolo[2,3-b]pyridin-5-ol (820 mg, 51.8% yield) as an oil, which solidified upon standing.
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