تفاعل #2636

معادلة التفاعل

tert-butyl methyl ether

lithium aluminum hydride

4-tert-butyldimethylsiloxy-2-cyclopentenone

lithium iodide

→

title compound

المردود 68.0%

cis-4-tert-butyldimethylsilyloxy-2-cyclopentenol

المردود 68.0%

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   أخرىthe temperature of the reaction at or
2. 2
   workup.ADDITIONbelow -15° C. (total addition time is approximately 3 minutes)
3. 3
   workup.STIRRINGThe reaction is stirred for 3 hours at -20° C.
4. 4
   أخرىit is quenched by slow addition of aqueous sodium hydroxide (1N, 250 mL) at a rate
5. 5
   أخرىthe temperature of the reaction below 20° C
6. 6
   ترشيحThe resulting suspension is then filtered through a pad of diatomaceous earth
7. 7
   غسيلthe pad is subsequently rinsed with toluene (400 mL)
8. 8
   أخرىThe filtrate phases are separated
9. 9
   استخلاصthe aqueous phase is extracted with toluene (450 mL)
10. 10
    استخلاصThe organic phase and organic extract
11. 11
    غسيلrinsed with aqueous sodium hydroxide (1N, 450 mL), brine (450 mL)
12. 12
    تجفيفdried over anhydrous magnesium sulfate
13. 13
    ترشيحfiltered
14. 14
    تركيزconcentrated under vacuum (40° C., 20 mmHg)
15. 15
    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 (175 g, 824 mmol) in anhydrous toluene (1.5L) under an atmosphere of argon is treated with lithium iodide (240 g, 1.79 mol). The mixture is cooled to -20° C. and treated with lithium aluminum hydride (13.5 g, 356 mmol) in one portion. The reaction is then stirred for 5 minutes and anhydrous tert-butyl methyl ether (300 mL) is added at a rate that maintains the temperature of the reaction at or below -15° C. (total addition time is approximately 3 minutes). The reaction is stirred for 3 hours at -20° C. and then it is quenched by slow addition of aqueous sodium hydroxide (1N, 250 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 (400 mL). The filtrate phases are separated and the aqueous phase is extracted with toluene (450 mL). The organic phase and organic extract are combined, rinsed with aqueous sodium hydroxide (1N, 450 mL), brine (450 mL), 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 (120 g, 68% yield) as a colorless oil; cis/trans/1-2 +1-4 addition, 92/4/4.

المصدر