CC1(C)C(C)(C)OB([C:9]2[CH:17]=[CH:16][C:15]3[N:14]4[CH2:18][CH2:19][C:20](=[CH:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[C:13]4=[CH:12][C:11]=3[CH:10]=2)O1.[OH-:30].[Na+].OO.Cl>C1COCC1>[OH:30][C:9]1[CH:17]=[CH:16][C:15]2[N:14]3[CH2:18][CH2:19][C:20](=[CH:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[C:13]3=[CH:12][C:11]=2[CH:10]=1To a solution of tert-butyl 2-(7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-ylidene)acetate (330 mg, 0.835 mmol) in THF (10 mL) was added a 2.0 M aqueous solution of sodium hydroxide (4.17 mL, 8.35 mmol). Then was added dropwise hydrogen peroxide (30 wt % aqueous solution, 0.853 mL, 8.35 mmol). The mixture was stirred at 23° C. for 25 min before 0.5 M HCl (50 mL) was added. The resulting mixture was extracted with dichloromethane (2×35 mL). The combined organic extracts were dried over MgSO4, filtered and concentrated under vacuum. The residue was purified by silica gel flash chromatography to provide the title compound as a pale yellow solid (186 mg). LCMS m/z=286.3 [M+H]+.
Wird geladen…
