تفاعل #2045099

معادلة التفاعل

(2E)-2-methyl-3-(4-methylphenyl)-2-propenal

lithium aluminum hydride

sodium sulfate

→

alcohol

المردود 93.7%

(2E)-2-methyl-3-(4-methylphenyl)-2-propen-1-ol

المردود 93.7%

المذيبات

THF

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe solution was cooled in an ice-water bath
2. 2
   درجة الحرارةto maintain the internal temperature below 20° C
3. 3
   أخرىThe cooling bath was removed
4. 4
   أخرىIt was then recooled in an ice-water bath
5. 5
   workup.ADDITIONWater (25 ml) was added slowly to the reaction
6. 6
   أخرىThe cooling bath was removed
7. 7
   workup.STIRRINGthe reaction stirred until a white slurry
8. 8
   أخرىwas obtained (30 minutes)
9. 9
   workup.STIRRINGAfter stirring for an additional 15 minutes
10. 10
    ترشيحthe solid was filtered off
11. 11
    غسيلthoroughly rinsed with diethyl ether
12. 12
    تركيزThe filtrate was then concentrated under vacuum
13. 13
    workup.DISTILLATIONThe product was purified by distillation through a 20-cm Widmer column

الإجراء التجريبي

(2E)-2-methyl-3-(4-methylphenyl)-2-propenal (320 g, 2 mol, described in Tet. Let., 28, 1987, 1263) was dissolved under nitrogen in dry THF (1 liter). The solution was cooled in an ice-water bath and solid lithium aluminum hydride (25 g, 0.63 mol) was added portion-wise at a rate such as to maintain the internal temperature below 20° C. The cooling bath was removed and the reaction stirred for 3 hours. It was then recooled in an ice-water bath. Water (25 ml) was added slowly to the reaction, followed by 5% aqueous NaOH (75 ml) and more water (25 ml). The cooling bath was removed and the reaction stirred until a white slurry was obtained (30 minutes). Solid anhydrous sodium sulfate (100 g) was added to the reaction. After stirring for an additional 15 minutes, the solid was filtered off and thoroughly rinsed with diethyl ether. The filtrate was then concentrated under vacuum. The product was purified by distillation through a 20-cm Widmer column. 304 g of the desired alcohol were obtained (1.78 mol, 89% yield).

المصدر