反应详情

Diol 22 (4.70 g, 19.2 mmol) was dissolved in cyclohexane (50 mL) and 48% HBr (2.4 mL, 21.2 mmol, 1.1 eq.) was added under vigorous stirring. The mixture was refluxed overnight. After cooling to r.t., saturated sodium bicarbonate solution (100 mL) was added and the phases were separated. The aqueous phase was extracted with dichloromethane (3×50 mL). The combined organic layers were dried over MgSO4. After evaporation of the solvent the product was purified by column chromatography (silica gel, 27×4 cm, cyclohexane/ethyl acetate, 4:1→100% ethyl acetate) and isolated as a white solid. Yield: 3.39 g (58%). Traces of 1,15-dibromopentadecane were also found.

1. temperatureThe mixture was refluxed overnight
2. customthe phases were separated
3. extractionThe aqueous phase was extracted with dichloromethane (3×50 mL)
4. dry with materialThe combined organic layers were dried over MgSO4
5. customAfter evaporation of the solvent the product
6. customwas purified by column chromatography (silica gel, 27×4 cm, cyclohexane/ethyl acetate, 4:1→100% ethyl acetate)
7. customisolated as a white solid