反应详情

To a solution of 3-benzyloxycarbonylamino-2-azetidinone (5.0 g) in dry tetrahydrofuran (125 ml), cooled to -78° C., was added sec-butyl lithium (18.5 ml) and the mixture was stirred for 5 minutes. Ethyl chlorophenylphosphonate (4.71 g) was added and the mixture was stirred for 1 hour at -78° C. followed by the addition of 125 ml of saturated sodium chloride solution. The mixture was then extracted twice with 125 ml portions of ethyl acetate and the extracts were combined, dried over anhydrous sodium sulfate and the solvent removed in vacuo yielding the crude product as a foam. The crude product was purified by chromatography on silica gel (750 g), eluting with dichloromethane:ethyl acetate (1:1) followed by ethyl acetate. The ethyl acetate fractions were stripped and the residue triturated with ether to yield 4.94 g of product.

1. stirringthe mixture was stirred for 1 hour at -78° C.
2. extractionThe mixture was then extracted twice with 125 ml portions of ethyl acetate
3. dry with materialdried over anhydrous sodium sulfate
4. customthe solvent removed in vacuo
5. customyielding the crude product as a foam
6. customThe crude product was purified by chromatography on silica gel (750 g)
7. washeluting with dichloromethane:ethyl acetate (1:1)
8. customthe residue triturated with ether