反应详情

A 250-mL round-bottomed flask equipped with a magnetic stirrer was charged with 150c (7.44 g, 1.0 eq., 30.0 mmol) and THF (100 mL). Under N2 protection, a solution of MeMgBr (3.0 Min ether) (25 mL, 2.5 eq., 75.0 mmol) was added at 0° C. The mixture was stirred at room temperature for 5 h and quenched with saturated NH4Cl solution (30 mL). The mixture was concentrated under reduced pressure and the residue was extracted with ethyl acetate (3×50 mL). The combined organic layer was evaporated under reduced pressure and the residue was purified by silica-gel column chromatography eluting with 4:1 petroleum ether/ethyl acetate to afford 150d as a white solid (5.40 g, 89%). MS-ESI: [M+H]+ 204.0. 1H NMR (500 MHz, CDCl3) δ 6.74 (s, 1H), 5.92 (s, 2H), 2.61 (s, 3H), 2.15 (s, 6H).

1. customA 250-mL round-bottomed flask equipped with a magnetic stirrer
2. customquenched with saturated NH4Cl solution (30 mL)
3. concentrationThe mixture was concentrated under reduced pressure
4. extractionthe residue was extracted with ethyl acetate (3×50 mL)
5. customThe combined organic layer was evaporated under reduced pressure
6. customthe residue was purified by silica-gel column chromatography
7. washeluting with 4:1 petroleum ether/ethyl acetate