反应详情

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°.

1. customdoes not exceed 5°
2. distillationAfter treatment with 12 ml of acetic acid the solvent is distilled off
3. customThe residue obtained
4. extractionis extracted twice with 200 ml of ether each time
5. washThe organic phase is washed with water
6. dry with materialdried over magnesium sulphate
7. customevaporated
8. customThe oil obtained
9. waitleft
10. customthe crystalline product obtained
11. customis recrystallized from ether/hexan