تفاعل #1244290

معادلة التفاعل

glucose

HCl

D-Glucose

ethyl 4-chloroacetoacetate

triethanolamine

Na2CO3

triethanolamine

→

ethyl (S) 4-chloro-3-hydroxybutyrate

المردود 85.9%

المذيبات

butyl acetate

water

H2O

ظروف التفاعل

المعالجة

1. 1
   أخرىTo a 3-necked jacketed 3 L flask equipped with a mechanical stirrer
2. 2
   workup.ADDITIONconnected to an automatic titrater by a pH electrode and a feeding tube for addition of base
3. 3
   أخرىwas set to 30° C
4. 4
   workup.WAITAfter 10 minutes
5. 5
   workup.ADDITIONCelite (16 g) was added
6. 6
   workup.STIRRINGto stir for 10 minutes
7. 7
   ترشيحThe solution was filtered through a celite pad
8. 8
   أخرىthe organic layer was separated
9. 9
   استخلاصThe aqueous layer was extracted with butyl acetate (2×200 mL)
10. 10
    أخرىthe solvent removed under vacuum by rotary evaporation

الإجراء التجريبي

To a 3-necked jacketed 3 L flask equipped with a mechanical stirrer and connected to an automatic titrater by a pH electrode and a feeding tube for addition of base, was charged triethanolamine (6.6 mL) and H2O (492 mL) to make 100 mM triethanolamine solution. The pH was adjusted to 7 with 37% HCl. Then, D-Glucose (125 g) was added. The water circulating to the flask jacket was set to 30° C. After 10 minutes, ketoreductase SEQ ID NO: 2 (5.7 g) and glucose dehydrogenase S06 SEQ ID NO: 10 (3.1 g) powder were added. After 10 minutes, β-NAD (125 mg) was added and the resulting mixture was allowed to stir for 5 minutes. Then, butyl acetate (250 mL) was charged. Using an addition funnel, 2.4 M ethyl 4-chloroacetoacetate (250 mL, 100 g in 167 mL of butyl acetate) was slowly added over 3 hrs. The pH was maintained at 7 by the automatic titrater by the addition of 2 M Na2CO3 (152 mL) over 15 hrs. Subsequently, gas chromatography of a reaction sample showed complete conversion to product. Celite (16 g) was added and the reaction mixture was allowed to stir for 10 minutes. The solution was filtered through a celite pad and the organic layer was separated. The aqueous layer was extracted with butyl acetate (2×200 mL). The organic layers were combined and the solvent removed under vacuum by rotary evaporation to obtain 87 g of the ethyl (S) 4-chloro-3-hydroxybutyrate. The enantiomeric excess was >99%, as determined after its conversion to ethyl (R)-4-cyano-3-hydroxybutyrate in Example 8.

المصدر