反应详情

A solution of 4-methylthio-1-(4-phenyl-2-oxobutyl)azetidin-2-one (0.4 g, 1.5 mmol) in dichloromethane (40 ml) was cooled to -60° C. To this a solution of meta-chloroperbenzoic acid (m-CPBA, 0.52 g, 1.5 mmol) in dry dichloromethane (50 ml) was added dropwise over 10 minutes, maintaining the temperature between -50 and -60° C. The mixture was stirred at room temperature for 60 minutes, washed with dil. Na2SO3, dil. NaHCO3, H2O (×2) and dried (MgSO4). Evaporation under reduced pressure gave a residue which was purified by flash chromatography on silica gel using ethyl acetate then petroleum ether/ethyl acetate to give 4-methylsulphinyl-1-(4-phenyl-2-oxobutyl)azetidin-2-one as a waxy yellow solid (0.18 g, 43%). 1H NMR demonstrated that this was a 1:1 mixture of diastereoisomers.

1. temperaturemaintaining the temperature between -50 and -60° C
2. washwashed with dil. Na2SO3, dil. NaHCO3, H2O (×2)
3. dry with materialdried (MgSO4)
4. customEvaporation under reduced pressure
5. customgave a residue which
6. customwas purified by flash chromatography on silica gel