تفاعل #707507

معادلة التفاعل

sodium borohydride

potassium hydroxide

rac-(2S*)-2-[(R*)-4-chloro-α-(nitromethyl)benzyl]cyclohexanone

→

rac-(1S*)-2-[(R*)-4-chloro-α-(nitromethyl)benzyl]cyclohexanol

المذيبات

water

ether pentane

water

water

methanol

ظروف التفاعل

المعالجة

1. 1
   أخرىdoes not exceed 5°
2. 2
   workup.DISTILLATIONAfter treatment with 12 ml of acetic acid the solvent is distilled off
3. 3
   أخرىThe residue obtained
4. 4
   استخلاصis extracted twice with 200 ml of ether each time
5. 5
   غسيلThe organic phase is washed with water
6. 6
   تجفيفdried over magnesium sulphate
7. 7
   أخرىevaporated
8. 8
   أخرىThe oil obtained
9. 9
   workup.WAITleft
10. 10
    أخرىthe crystalline product obtained
11. 11
    أخرىis recrystallized from ether/hexan

الإجراء التجريبي

A solution of 6.8 g (121 mmol) of potassium hydroxide in 40 ml of water is added dropwise while cooling within about 30 minutes to a solution of 28.2 g (100 mmol) of rac-(2S*)-2-[(R*)-4-chloro-α-(nitromethyl)benzyl]cyclohexanone in 200 ml of methanol so that the temperature does not exceed 5°. An ice-cold solution of 2.85 g (75 mmol) of sodium borohydride in 20 ml of water is subsequently added dropwise, whereupon the mixture is stirred at 0° for 3 hours. After treatment with 12 ml of acetic acid the solvent is distilled off. The residue obtained is treated with water, whereupon the mixture is extracted twice with 200 ml of ether each time. The organic phase is washed with water, dried over magnesium sulphate and evaporated. The oil obtained is taken up in ether/pentane, left to stand in a refrigerator and the crystalline product obtained is recrystallized from ether/hexan. There is obtained rac-(1S*)-2-[(R*)-4-chloro-α-(nitromethyl)benzyl]cyclohexanol of m.p. 82°-84°.

المصدر