反应详情

1.8 ml (13.0 mmol - 2.6 equivalents) of triethylamine and then 2.3 ml (12.0 mmol - 2.4 equivalents) of trimethylsilyl trifluoromethanesulphonate were added to a solution, which had been cooled to 0° C., of 646 mg (5.0 mmol) of 4-acetoxy-2-azetidinone and 1.42 g (6.5 mmol) of tert.-butyl 4-chloro-2-diazo-3-oxobutanoate in 45 ml of anhydrous dichloromethane. The cooling bath was removed and the mixture was stirred at room temperature for 5 h, then 0.3 ml (1.5 mmol - 0.3 equivalent) of trimethylsilyl trifluoromethanesulphonate was added and the mixture was stirred at room temperature for 1 h. To work up, it was poured into a mixture of cold saturated NaHCO3 solution and ethyl acetate, extraction with ethyl acetate was carried out, and the organic extracts were washed with saturated NaCl solution and dried over MgSO4. After evaporation of the solvent in vacuo and chromatography on 40 g of silica gel (toluene:ethyl acetate 1:1), 426 mg (30%) of the title compound were obtained as a mixture of diastereomers (10:1), Rf: 0.35 (toluene:ethyl acetate 1:1).

1. customThe cooling bath was removed
2. addition0.3 ml (1.5 mmol - 0.3 equivalent) of trimethylsilyl trifluoromethanesulphonate was added
3. stirringthe mixture was stirred at room temperature for 1 h
4. additionit was poured into a mixture of cold saturated NaHCO3 solution and ethyl acetate, extraction with ethyl acetate
5. washthe organic extracts were washed with saturated NaCl solution
6. dry with materialdried over MgSO4
7. customAfter evaporation of the solvent in vacuo and chromatography on 40 g of silica gel (toluene:ethyl acetate 1:1)