反应详情

50 g (0.226 mmol) of 2 were dissolved in 450 cm3 of THF/MeOH (2:1), and 12.8 g (0.34 mol) of sodium borohydride were added in portions at 0° C. with stirring. The reaction mixture was stirred for a further 18 hours and poured into ice, concentrated HCl was added to pH 1 and the mixture was extracted a number of times with Et2O. The combined organic phases were washed with saturated aqueous NaHCO3 solution and NaCl solution and then dried (MgSO4). The solvent was removed in vacuo, and the crude product, without further purification, was taken up in 1 dm3 of toluene, 2 g of p-toluene sulfonic acid were added, and the mixture was refluxed for 2 hours. The reaction mixture was washed with 200 cm3 of saturated aqueous NaHCO3 solution, and the solvent was removed in vacuo. The crude product was purified by filtration through 500 g of silica gel (hexane/CH2Cl2), giving 42 g (90%) of 3 as a colorless oil.

1. stirringThe reaction mixture was stirred for a further 18 hours
2. additionwas added to pH 1
3. extractionthe mixture was extracted a number of times with Et2O
4. washThe combined organic phases were washed with saturated aqueous NaHCO3 solution and NaCl solution
5. dry with materialdried (MgSO4)
6. customThe solvent was removed in vacuo
7. customthe crude product, without further purification
8. addition2 g of p-toluene sulfonic acid were added
9. temperaturethe mixture was refluxed for 2 hours
10. washThe reaction mixture was washed with 200 cm3 of saturated aqueous NaHCO3 solution
11. customthe solvent was removed in vacuo
12. filtrationThe crude product was purified by filtration through 500 g of silica gel (hexane/CH2Cl2)