Methanol → Butanoic acid, 4-chloro-3-hydroxy-, ethyl ester

Temperatur

80 °C

Ozone was introduced into a mixture of 225.5 mg (1 mmol) of (+)-2,2-dimethyl-(3-chloro-2-hydroxypropyl)-1,3-dioxin-4-one (96% ee) obtained in Example 4 and 20 ml of methanol at -78° C. for 5 hours, and 2 ml of dimethyl sulfide were added thereto, followed by stirring at the same temperature for 2 hours. The temperature was gradually returned to room temperature, and the solution was then stirred for 5 hours. Afterward, the solvent was distilled off, and the resultant residue was then dissolved in ethanol. 3 drops of concentrated sulfuric acid were added thereto, and the solution was then heated at 80° C. for 30 minutes. Next, ethanol was distilled off, and the residue was diluted with water. The solution was extracted with dichloromethane and then dried over anhydrous sodium sulfate, and the solvent was distilled off and the residue was then subjected to column chromatography (an eluent of hexane:ethyl acetate=5:1), thereby obtaining 109.4 mg (yield 66%) of (+)-ethyl 4-chloro-3-hydroxybutanoate.

1. customwas gradually returned to room temperature
2. stirringthe solution was then stirred for 5 hours
3. distillationAfterward, the solvent was distilled off
4. dissolutionthe resultant residue was then dissolved in ethanol
5. addition3 drops of concentrated sulfuric acid were added
6. distillationNext, ethanol was distilled off
7. additionthe residue was diluted with water
8. extractionThe solution was extracted with dichloromethane
9. dry with materialdried over anhydrous sodium sulfate
10. distillationthe solvent was distilled off

ORD-Eintrag

ord-d4141169b3a64ab4b95d97dc751e2fd7

Quelldatensatz

uspto-grants-1994_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05292891