反应详情

In an argon atmosphere, 4.7 mL (F.W. 270.70, d=2.850, 49.5 mmol) of phosphorus tribromide was added to a solution of 46 g (F.W. 339.19, 135 mmol) of alcohol (23) in 100 mL of methylene chloride at 0° C. and stirred at room temperature for 30 minutes. To the reaction mixture was added ice water and the resulting solution was further stirred at room temperature for 30 minutes. The obtained solution was extracted with ethyl acetate and the extract was washed with water and then with a saturated sodium chloride aqueous solution. The resulting extract was dried with anhydrous magnesium sulfate and then, concentrated. The residue was purified by silica gel column chromatography (developing solvent; ethyl acetate:hexane=1:5) to obtain 44.6 g (84%) of a bromide (24). (TLC; ethyl acetate:hexane=1:4).

1. stirringthe resulting solution was further stirred at room temperature for 30 minutes
2. extractionThe obtained solution was extracted with ethyl acetate
3. washthe extract was washed with water
4. extractionThe resulting extract
5. dry with materialwas dried with anhydrous magnesium sulfate
6. concentrationconcentrated
7. customThe residue was purified by silica gel column chromatography (developing solvent; ethyl acetate:hexane=1:5)