反应详情

To a nitrogen flushed 100 mL round bottom flask were added 6-bromo-2,2-dimethyl-3,4-dihydro-2H-chromene (0.41 g, 1.7 mmol) and THF (6 mL). A solution of n-BuLi in hexanes (0.69 mL, 2.6 M, 1.79 mmol) was added at −78° C. The resulting reaction mixture was stirred at −78° C. for 10 minutes when DMF (0.20 mL, 2.55 mmol) was added. The reaction mixture was allowed to warm to room temperature and was diluted with EtOAc (25 mL). It was stirred over wet silica gel (10 g silica gel/0.5 mL water) for 10 minutes and was filtered. The solid was rinsed with EtOAc and the filtrate was concentrated. The residue was purified on a silica gel column eluting with a gradient of 100% hexanes to 20% EtOAc/hexanes to give the title intermediate (0.25 g) as a light yellow oil.

1. customTo a nitrogen flushed 100 mL round bottom flask
2. customThe resulting reaction mixture
3. additionwas added
4. filtrationwas filtered
5. washThe solid was rinsed with EtOAc
6. concentrationthe filtrate was concentrated
7. customThe residue was purified on a silica gel column
8. washeluting with a gradient of 100% hexanes to 20% EtOAc/hexanes