反应详情

Titanium tetrachloride (0.66 mL, 6.06 mmol) was slowly added to a slurry of Zn powder (0.81 g, 12.4 mmol) in dry THF (14 mL). The reaction mixture was heated at reflux for 2.5 h. A solution of 3,3,5,5-tetramethyl-cyclohexanone (0.86 mL, 4.91 mmol) and N-[4-(4-methoxy-benzoyl)-phenyl]-methanesulfonamide (179) (0.5 g, 1.64 mmol) in dry THF (14 mL) was added to the reaction mixture and heated at reflux for another 2 h. The reaction mixture was cooled to room temperature and diluted with water (10 mL) followed by 10% K2CO3 (10 mL). The reaction mixture was filtered through a pad of Celite and the pad was washed with EtOAc. The filtrate was transferred to a separatory funnel and the layers were separated. The aqueous layer was extracted with EtOAc and the combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated. The crude material was loaded onto silica gel and purified by flash chromatography with a hexanes:EtOAc gradient (100:0 to 60:40) to give 0.5 g (71%) of the title compound 180 as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 0.87 (s, 6H), 0.87 (s, 6H), 1.24 (s, 2H), 1.88-1.89 (m 4H), 2.95 (s, 3H), 3.70 (s, 3H), 6.83 (d, J=8.8 Hz, 2H), 7.03 (d, J=8.6 Hz, 2H), 7.08 (m, 4H), 9.66 (s, 1H).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 2.5 h
3. temperatureheated
4. temperatureat reflux for another 2 h
5. filtrationThe reaction mixture was filtered through a pad of Celite
6. washthe pad was washed with EtOAc
7. customThe filtrate was transferred to a separatory funnel
8. customthe layers were separated
9. extractionThe aqueous layer was extracted with EtOAc
10. washthe combined organic layers were washed with brine
11. dry with materialdried over Na2SO4
12. filtrationfiltered
13. concentrationconcentrated
14. custompurified by flash chromatography with a hexanes