Reaktion #1244292

Reaktionsgleichung

Ethyl 4-chloroacetoacetate

glucose

NaOH

NADP

→

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

Ausbeute 87.4%

Lösungsmittel

Butyl acetate

water

Reaktionsbedingungen

Aufarbeitung

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
   Sonstigeto separate
6. 6
   Sonstigewas separated
7. 7
   Waschenwashed with 10 mL of water
8. 8
   ExtraktionThe combined aqueous layers were extracted twice with 20 mL of butyl acetate
9. 9
   Sonstigerotary evaporated under vacuum
10. 10
    Sonstigeto remove water
11. 11
    workup.ADDITIONAdditional butyl acetate was added during the evaporation
12. 12
    Sonstigeto help remove the water
13. 13
    SonstigeWhen the water was removed the butyl acetate solution
14. 14
    Sonstigewas decanted from solids in the flask
15. 15
    SonstigeEvaporation of the solvent under vacuum

Vorschrift

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.

Quelle