反应详情

To a solution of ethyl 2-hydroxyimino-3,3-ethylenedioxybutyrate (syn isomer, 5 g) in dried ethyl acetate (20 ml) was added potassium carbonate (5.78 g), and dimethyl sulfate (3.96 ml) was added dropwise thereto at ambient temperature with stirring, and then the mixture was stirred for 2 hours at 43°-45° C. To the reaction mixture were added water (10 ml) and ethyl acetate (5 ml), and the mixture was stirred for 40 minutes at ambient temperature. The mixture was adjusted to pH 7.2 with 6N hydrochloric acid and saturated with sodium chloride, and then ethyl acetate layer was separated. The remaining aqueous layer was further extracted with ethyl acetate (10 ml). The ethyl acetate layer and extract were combined together, washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and then filtered. The filtrate was evaporated to give ethyl 2-methoxyimino-3,3-ethylenedioxybutyrate (syn isomer), quantitatively.

1. additionwas added dropwise
2. stirringthe mixture was stirred for 2 hours at 43°-45° C
3. stirringthe mixture was stirred for 40 minutes at ambient temperature
4. customethyl acetate layer was separated
5. extractionThe remaining aqueous layer was further extracted with ethyl acetate (10 ml)
6. extractionThe ethyl acetate layer and extract
7. washwashed with a saturated aqueous solution of sodium chloride
8. dry with materialdried over magnesium sulfate
9. filtrationfiltered
10. customThe filtrate was evaporated