반응 #2638

반응 방정식

tert-butyl methyl ether

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium bromide

lithium aluminum hydride

→

title compound

수율 69.2%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

수율 69.2%

용매

toluene

반응 조건

후처리

1. 1
   기타It is then quenched by slow addition of aqueous sodium hydroxide (1N, 7.0 mL) at a rate
2. 2
   기타the temperature of the reaction below 20° C
3. 3
   여과The resulting suspension is then filtered through a pad of diatomaceous earth
4. 4
   세척the pad is subsequently rinsed with toluene
5. 5
   기타The filtrate phases are separated
6. 6
   추출the aqueous phase is extracted with toluene
7. 7
   추출The organic phase and organic extract
8. 8
   세척rinsed with aqueous sodium hydroxide (1N), brine
9. 9
   건조dried over anhydrous magnesium sulfate
10. 10
    여과filtered
11. 11
    농축concentrated under vacuum (40° C., 20 mmHg)
12. 12
    workup.DISTILLATIONThe residue is then purified by Kugelrohr distillation (60°-80° C., 1 mmHg)

실험 절차

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.

출처