反应详情

To a solution of ethyl 3-keto-2-methyl-4,4,4-trifluorobutanoate (20.1 g, 0.10 moles) in 250 ml of absolute ethanol, cooled in an ice bath, was added sodium borohydride (1.0 g, 0.25 moles) in portions with stirring. The cooling bath was removed and the reaction stirred at room temperature for 30 minutes. Acetone (5 ml) was added to quench any remaining sodium borohydride and the solvents removed by distillation at atmospheric pressure using a Vigreaux column. The residue was diluted with 200 ml of methylene chloride and poured into a separatory funnel containing 75 ml of a 1:1:1 mixture of saturated ammonium chloride:brine:water. The layers were separated and the aqueous phase extracted with methylene chloride (3×25 ml). The combined organic phase and methylene chloride extracts were dried over magnesium sulfate, filtered and distilled at atmospheric pressure to remove the solvents. The residue was then distilled at reduced pressure (20 mmHg) using a Vigreaux column to give ethyl 3-hydroxy-2-methyl-4,4,4-trifluorobutanoate, bp 78°-84° C., 20 mmHg.

1. customThe cooling bath was removed
2. stirringthe reaction stirred at room temperature for 30 minutes
3. additionAcetone (5 ml) was added
4. customto quench any remaining sodium borohydride
5. customthe solvents removed by distillation at atmospheric pressure
6. additionThe residue was diluted with 200 ml of methylene chloride
7. additionpoured into a separatory funnel
8. additioncontaining
9. addition75 ml of a 1:1:1 mixture of saturated ammonium chloride
10. customThe layers were separated
11. extractionthe aqueous phase extracted with methylene chloride (3×25 ml)
12. dry with materialThe combined organic phase and methylene chloride extracts were dried over magnesium sulfate
13. filtrationfiltered
14. distillationdistilled at atmospheric pressure
15. customto remove the solvents
16. distillationThe residue was then distilled at reduced pressure (20 mmHg)