تفاعل #1551089

معادلة التفاعل

3-tert-butyldimethylsilyloxybutan-2-one

3-benzyloxy-5-fluorophenylmagnesium bromide

tert-butyldimethylsilyl chloride

imidazole

benzyl 3-bromo-5-fluorophenyl ether

magnesium

3-hydroxybutan-2-one

→

tert-butyldimethylsilyloxybutan-2-ol

المردود 41.0%

المذيبات

diethyl ether

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   أخرىprepared
2. 2
   أخرىprepared
3. 3
   درجة الحرارةby heating
4. 4
   أخرىThe mixture was evaporated
5. 5
   أخرىthe residue was partitioned between diethyl ether and water
6. 6
   غسيلThe organic phase was washed with a saturated aqueous sodium chloride solution
7. 7
   تجفيفdried (MgSO4)
8. 8
   أخرىevaporated
9. 9
   أخرىThe residue was purified by column chromatography
10. 10
    workup.ADDITIONa 3:2 v/v mixture of petroleum ether (b.p. 40°-60° C.) and methylene chloride as eluent

الإجراء التجريبي

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-butyldimethylsilyloxybutan-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.

المصدر