反应详情

(3S,4S)-4-(1-Formylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone (4.5 g) was dissolved in t-butanol (380 ml). After addition of 2-methyl-2-butene (42.5 ml) thereto, there was dropwise added an aqueous solution (72.3 ml) of sodium chlorite (7.15 g) and disodium hydrogenphosphate (7.15 g). The resulting mixture was stirred at room temperature for 1 hour and concentrated in vacuo at 40° C. or lower. The concentrate was diluted with ethyl acetate (150 ml) and water (75 ml), and the organic layer was separated. The aqueous layer was extracted with ethyl acetate (80 ml), and the combined ethyl acetate layer was washed with brine (150 ml) and extracted with a saturated sodium bicarbonate solution (150 ml). The alkaline layer was acidified with conc. hydrochloric acid under ice-cooling and extracted with ethyl acetate. The extracts were washed with brine and dried over anhydrous sodium sulfate. Filtration and concentration of the filtrate in vacuo gave (3S,4S)-4-(1-carboxyethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone.

1. concentrationconcentrated in vacuo at 40° C.
2. additionThe concentrate was diluted with ethyl acetate (150 ml) and water (75 ml)
3. customthe organic layer was separated
4. extractionThe aqueous layer was extracted with ethyl acetate (80 ml)
5. washthe combined ethyl acetate layer was washed with brine (150 ml)
6. extractionextracted with a saturated sodium bicarbonate solution (150 ml)
7. temperaturecooling
8. extractionextracted with ethyl acetate
9. washThe extracts were washed with brine
10. dry with materialdried over anhydrous sodium sulfate
11. filtrationFiltration and concentration of the filtrate in vacuo