تفاعل #2638

معادلة التفاعل

tert-butyl methyl ether

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium bromide

lithium aluminum hydride

→

title compound

المردود 69.2%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

المردود 69.2%

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   أخرىIt is then quenched by slow addition of aqueous sodium hydroxide (1N, 7.0 mL) at a rate
2. 2
   أخرىthe temperature of the reaction below 20° C
3. 3
   ترشيحThe resulting suspension is then filtered through a pad of diatomaceous earth
4. 4
   غسيلthe pad is subsequently rinsed with toluene
5. 5
   أخرىThe filtrate phases are separated
6. 6
   استخلاصthe aqueous phase is extracted with toluene
7. 7
   استخلاصThe organic phase and organic extract
8. 8
   غسيلrinsed with aqueous sodium hydroxide (1N), brine
9. 9
   تجفيفdried over anhydrous magnesium sulfate
10. 10
    ترشيحfiltered
11. 11
    تركيزconcentrated under vacuum (40° C., 20 mmHg)
12. 12
    workup.DISTILLATIONThe residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg)

الإجراء التجريبي

A mechanically stirred solution of 4-tert-butyldimethylsiloxy-2-cyclopentenone (501 mg, 2.36 mmol) in anhydrous toluene (10 mL) under an atmosphere of argon is treated with lithium bromide (1.06 g, 12.2 mmol). The mixture is cooled to -20° C. with an ice/salt bath and treated with lithium aluminum hydride (92.0 mg, 2.42 mmol) in one portion followed by tert-butyl methyl ether (1.0 mL). The ice/salt bath is replaced with an ice bath and the reaction is then stirred for 2 hours at 0° C. It is then quenched by slow addition of aqueous sodium hydroxide (1N, 7.0 mL) at a rate that maintains the temperature of the reaction below 20° C. The resulting suspension is then filtered through a pad of diatomaceous earth and the pad is subsequently rinsed with toluene. The filtrate phases are separated and the aqueous phase is extracted with toluene. The organic phase and organic extract are combined, rinsed with aqueous sodium hydroxide (1N), brine, dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum (40° C., 20 mmHg). The residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg) to provide the title compound (350 mg, 69% yield) as a colorless oil; cis/trans/1-2+1-4 addition, 92.7/6.3/1.0.

المصدر