反应详情

A solution of (±)-(cis)-[(3-azido-1-(4-methoxyphenyl)-2-oxo-4-azetidinyl)methoxy]acetic acid, methyl ester (2.054 g, 6.44 mmole) in acetonitrile (40 ml) was cooled to -5° C. A solution of ceric ammonium nitrate (10.62 g, 19.32 mmole) in water (30 ml) was added rapidly over ca. forty-five seconds. The reaction was warmed to +10° C. over fifteen minutes, diluted with water (100 ml), and extracted with ethyl acetate (two 80 ml portions). Sodium chloride was added to the aqueous layer which was again extracted with ethyl acetate (ca. 150 ml). The organic extracts were washed with saturated potassium bicarbonate, saturated sodium sulfite solution, brine, and dried (sodium sulfate). Filtration followed by solvent removal yielded 1.56 g of crude product which was chromatographed on silica gel (55 g, 230-400 mesh). Elution with 70% ethyl acetate-hexane yielded 1.1 g of the title compound as a heavy oil.

1. temperatureThe reaction was warmed to +10° C. over fifteen minutes
2. extractionextracted with ethyl acetate (two 80 ml portions)
3. additionSodium chloride was added to the aqueous layer which
4. extractionwas again extracted with ethyl acetate (ca. 150 ml)
5. washThe organic extracts were washed with saturated potassium bicarbonate, saturated sodium sulfite solution, brine
6. dry with materialdried (sodium sulfate)
7. filtrationFiltration
8. customfollowed by solvent removal
9. customyielded 1.56 g of crude product which
10. customwas chromatographed on silica gel (55 g, 230-400 mesh)
11. washElution with 70% ethyl acetate-hexane