[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([CH2:14][CH:15]=C)=[C:8]([CH:13]=1)[C:9]([O:11][CH3:12])=[O:10])([O-:3])=[O:2].C[N+]1([O-])CC[O:21]CC1.I([O-])(=O)(=O)=O.[Na+]>O.C1COCC1.CCOC(C)=O.[Os](=O)(=O)(=O)=O>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([CH2:14][CH:15]=[O:21])=[C:8]([CH:13]=1)[C:9]([O:11][CH3:12])=[O:10])([O-:3])=[O:2]To a solution of Methyl 5-nitro-2-(prop-2-en-1-yl)benzoate (0.20 g, 0.90 mmol) in water (2 mL) and THF (5 mL) was added osmium tetroxide (0.57 mL 2.5% solution, 0.045 mmol) and NMO (0.16 g, 1.4 mmol). The mixture was allowed to stir at RT for 16 hours and monitored by TLC. The reaction was diluted with EtOAc, washed with NH4Cl and brine, and concentrated. The residue was redissolved in MeOH and water. After cooling the solution to 0° C., an aqueous solution of sodium periodate (0.39 g, 1.8 mmol) was dropped into the reaction and allowed to stir for 2 hours. The reaction was diluted with water, extracted with EtOAc, dried over sodium sulfate, and concentrated. The crude residue was purified by silica gel chromatography to provide Methyl 5-nitro-2-(2-oxoethyl)benzoate. 1H-NMR (400 MHz, CDCl3) δ ppm 9.48 (S, 1H), 8.97 (s, 1H), 8.39 (d, J=8.0 Hz, 1H), 7.46 (d, J=8.0 Hz, 1H), 4.31 (s, 2H), 3.98 (s, 3H).
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