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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

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