反应详情

A solution of (3S,4R)-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-4-(3-triphenylphosphoranylidene-2-oxopropyl)-2-oxoazetidine (572 mg) and (2S)-1-allyloxycarbonyl-2-formylpyrrolidine (201.5 mg) in toluene (5 ml) was heated to reflex for three hours. Evaporation of the solvent gave a residue, which was taken up into ethyl acetate. The resultant precipitate was filtered off and washed with ethyl acetate. The filtrate and the washings were combined and evaporated in vacuo. The residue was chromatographed on silica gel (50 ml) eluting with a mixture of n-hexane and ethyl acetate (2:1-1:1-1:3 V/V) to give (3S,4R)-4-[(E)-4-{(2S)-1-allyloxycarbonylpyrrolidin-2-yl}-2-oxo-3-butenyl]-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidine (297.7 mg).

1. customEvaporation of the solvent
2. customgave a residue, which
3. filtrationThe resultant precipitate was filtered off
4. washwashed with ethyl acetate
5. customevaporated in vacuo
6. customThe residue was chromatographed on silica gel (50 ml)
7. washeluting with a mixture of n-hexane and ethyl acetate (2:1-1:1-1:3 V/V)