[C:1]([O:5][C:6]([NH:8][CH2:9][CH2:10][C:11]1[C:12]([O:30][CH3:31])=[N:13][C:14]([C:26]([F:29])([F:28])[F:27])=[CH:15][C:16]=1[CH2:17][O:18][Si](C(C)(C)C)(C)C)=[O:7])([CH3:4])([CH3:3])[CH3:2].[F-].C([N+](CCCC)(CCCC)CCCC)CCC>O1CCCC1>[C:1]([O:5][C:6]([NH:8][CH2:9][CH2:10][C:11]1[C:12]([O:30][CH3:31])=[N:13][C:14]([C:26]([F:27])([F:28])[F:29])=[CH:15][C:16]=1[CH2:17][OH:18])=[O:7])([CH3:3])([CH3:4])[CH3:2]To a solution of the compound from Step K above (1.12 g, 2.41 mmol) in tetrahydrofuran (20 mL) was added tetrabutylammonium fluoride (11.0M in tetrahydrofuran, 2.41 mL, 2.41 mmol). The reaction was then stirred at room temperature for 10 min and concentrated under reduced pressure. The residue was purified by flash chromatography (silica gel; 20% to 40% ethyl acetate/hexanes gradient elution) to afford the title compound. 1H NMR (400 MHz, CDCl3) δ 7.38 (s, 1H), 4.87 (br s, 1H), 4.76 (d, 2H, J=6 Hz), 4.02 (s, 3H), 3.54 (t, 1H), 3.35 (m, 2H), 2.88 (t, 2H, J=6 Hz), 1.38 (s, 9H).
Wird geladen…