反应详情

温度

-20 °C

To a solution of (3S,4R)-4-[2-(1-allyloxycarbonylpyrrolidin-3-yl)-2-oxoethyl]-3-[(1R)-1-t-butyldimethylsilyloxyethyl]-2-oxoazetidine (2.13 g) and triethylamine (1.4 ml) in dichloromethane (30 ml) was added allyl oxalyl chloride (1.1 g) at -20° C. under nitrogen, and the resulting mixture was stirred for 30 minutes at -20° C. The reaction mixture was taken up into a mixture of water and ethyl acetate. The organic layer was separated, washed in turn with water, aqueous sodium hydrogen carbonate and brine, dried over magnesium sulfate, and evaporated. To a solution of the residue in xylene (30 ml) was added triethyl phosphite (5.2 ml). The resulting mixture was heated at 90° C. for 15 hours under nitrogen, and then to the mixture was added hydroquinone (0.9 g) and the mixture was heated at 130° C. for 2 hours under nitrogen. Evaporation of the solvent gave a residue, which was chromatographed on silica gel eluting with a mixture of n-hexane and ethyl acetate (4:1, V/V) to give allyl (5R,6S)-3-(1-allyloxycarbonylpyrrolidin-3-yl)-6-[(1R)-1-t-butyldimethylsilyloxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (2.9 g).

1. customThe organic layer was separated
2. washwashed in turn with water, aqueous sodium hydrogen carbonate and brine
3. dry with materialdried over magnesium sulfate
4. customevaporated
5. additionTo a solution of the residue in xylene (30 ml) was added triethyl phosphite (5.2 ml)
6. temperatureThe resulting mixture was heated at 90° C. for 15 hours under nitrogen
7. additionto the mixture was added hydroquinone (0.9 g)
8. temperaturethe mixture was heated at 130° C. for 2 hours under nitrogen
9. customEvaporation of the solvent
10. customgave a residue, which
11. customwas chromatographed on silica gel eluting with a mixture of n-hexane and ethyl acetate (4:1, V/V)