反应详情

A solution of 3-tert-butyldimethylsilyloxybutan-2-one (5.56 g; prepared by reacting 3-hydroxybutan-2-one with tert-butyldimethylsilyl chloride in diethyl ether and using imidazole as a suitable base) in tetrahydrofuran (5 ml) was added to a solution of 3-benzyloxy-5-fluorophenylmagnesium bromide [prepared by heating a mixture of benzyl 3-bromo-5-fluorophenyl ether (6.7 g), magnesium powder (0.58 g) and tetrahydrofuran (50 ml) to 40° C. for 1 hour] in tetrahydrofuran (50 ml) and the mixture was stirred at ambient temperature for 2.5 hours. The mixture was evaporated and the residue was partitioned between diethyl ether and water. The organic phase was washed with a saturated aqueous sodium chloride solution, dried (MgSO4) and evaporated. The residue was purified by column chromatography using a 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent. There was thus obtained an erythro isomer, (2RS,3SR)-2-(3-benzyloxy-5-fluorophenyl)-3-(tert-butyldimethylsilyloxy)butan-2-ol (3.8 g, 41%), as an oil; and a threo isomer, the corresponding (2RS,3RS)-isomer (1.73 g, 18%), as an oil.

1. customprepared
2. customprepared
3. temperatureby heating
4. customThe mixture was evaporated
5. customthe residue was partitioned between diethyl ether and water
6. washThe organic phase was washed with a saturated aqueous sodium chloride solution
7. dry with materialdried (MgSO4)
8. customevaporated
9. customThe residue was purified by column chromatography
10. additiona 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent