反应 #1244292

反应方程式

Ethyl 4-chloroacetoacetate

glucose

NaOH

NADP

→

ethyl (S)-4-chloro-3-hydroxybutyrate

收率 87.4%

溶剂

Butyl acetate

water

反应条件

后处理

1. 1
   workup.ADDITIONTo a 100 mL vessel connected to an automatic titrater by a pH electrode and a feeding tube for addition of base
2. 2
   workup.ADDITIONTo this solution was charged ketoreductase SEQ ID NO
3. 3
   workup.ADDITION1 mL was charged rapidly
4. 4
   workup.ADDITIONthe remainder was then charged at a rate of 1 mL/hr)
5. 5
   其他to separate
6. 6
   其他was separated
7. 7
   洗涤washed with 10 mL of water
8. 8
   萃取The combined aqueous layers were extracted twice with 20 mL of butyl acetate
9. 9
   其他rotary evaporated under vacuum
10. 10
    其他to remove water
11. 11
    workup.ADDITIONAdditional butyl acetate was added during the evaporation
12. 12
    其他to help remove the water
13. 13
    其他When the water was removed the butyl acetate solution
14. 14
    其他was decanted from solids in the flask
15. 15
    其他Evaporation of the solvent under vacuum

实验过程

To a 100 mL vessel connected to an automatic titrater by a pH electrode and a feeding tube for addition of base was charged a solution of glucose (12. g) in water (30 mL). To this solution was charged ketoreductase SEQ ID NO: 42 (100 mg); 50 mg GDH SEQ ID NO: 66 and NADP (6.25 mg). Butyl acetate (10 ml) was then charged. Ethyl 4-chloroacetoacetate (10 g) was then charged via syringe pump as follows: 1 mL was charged rapidly and the remainder was then charged at a rate of 1 mL/hr). The pH was maintained at 7 by the automatic titrater by the addition of 4M NaOH over 18 hours hrs. The stirring was stopped and the phases allowed to separate. The organic layer included some emulsion. The organic layer, including some emulsion, was separated and washed with 10 mL of water. The combined aqueous layers were extracted twice with 20 mL of butyl acetate. The organic extracts were combined and rotary evaporated under vacuum to remove water. Additional butyl acetate was added during the evaporation to help remove the water. When the water was removed the butyl acetate solution was decanted from solids in the flask. Evaporation of the solvent under vacuum then gave 8.85 g of ethyl (S)-4-chloro-3-hydroxybutyrate (87.4% yield) of very good purity.

来源