反应详情

To a cooled (-78° C.) solution of lithium diisopropylamide (20 mmol) in a mixture of THF (20 mL) and hexane (8 mL) (obtained in situ from the corresponding diisopropylamine and n-BuLi) was added slowly the compound obtained in step 1(3.96 g, 18 mmol) in anhyd. THF(10 mL). The mixture was stirred for 30 minutes and 1,8-diiodooctane (7.19 g, 20 mmol) in hexamethylphosphoramide (3.50 g, 20 mmol), was added. The mixture was stirred at -78° C. for 30 minutes, slowly brought to 0° C. over a period of 2 h and quenched by the cautious addition of 50 mL of 12% aqueous sodium chloride solution. The mixture was extracted with ether, washed with brine, dried and the solvent was evaporated. The crude product was purified to an oil (3.23 g) by a flash chromatography over silica using hexane to 1% EtOAc in hexane as an eluant; 1H NMR (300 MHz, CDCl3) δ: 7.35(m, 5H), 5.15(s,2H), 3.20(t,8 Hz,2H), 2.20(m, 1H), 2.0(m, 1H), 1.2-1.8(m,22H)

1. stirringThe mixture was stirred at -78° C. for 30 minutes
2. waitslowly brought to 0° C. over a period of 2 h
3. customquenched by the cautious addition of 50 mL of 12% aqueous sodium chloride solution
4. extractionThe mixture was extracted with ether
5. washwashed with brine
6. customdried
7. customthe solvent was evaporated
8. customThe crude product was purified to an oil (3.23 g) by a flash chromatography over silica