反应详情

To a solution of Example 123B (7.72 g, 36.1 mmol) in benzene (400 mL) was added celite (15 g), pyridinium dichromate (54.3 g, 144.3 mmol) and tert-butylhydroperoxide (70% in water) (19.9 mL, 144.3 mmol). The resultant solution was stirred at room temperature for 1.25 hours, followed by filtering the solution through a plug of celite (20 g) which was rinsed with benzene (100 mL). The combined filtrate was concentrated in vacuo, and the resultant residue was purified by column chromatography employing 70-230 mesh silica gel eluting with a mixture of 20% ethyl acetate in hexane followed by 50% ethyl acetate in hexane to provide the title compound as a light yellow oil (2.05 g, 25%). 1H NMR (300 MHz, DMSO-d6): δ 1.53 (s, 3H), 2.77 (m, 2H), 3.82 (s, 3H), 4.75 (m, 2H), 5.02 (m, 1H), 5.84 (s, 1H), 7.42 (m, 1H), 7.65 (dt, J=8.1, 1.5 Hz, 1H), 7.76 (d, J=8.1 Hz, 1H), 7.96 (dd, J=7.7, 1.5 Hz, 1H).

1. filtrationby filtering the solution through a plug of celite (20 g) which
2. washwas rinsed with benzene (100 mL)
3. concentrationThe combined filtrate was concentrated in vacuo
4. customthe resultant residue was purified by column chromatography
5. additionwith a mixture of 20% ethyl acetate in hexane