反应详情

温度

25 °C

trans i.e. (3S,4S)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone (0.08 g) is dissolved in a mixture of tetrahydrofuran (10 ml) and water (2 ml), and 0.02 g of mercury sulfate and a catalytic amount of concentrated sulfuric acid are added, followed by stirring at 25° C. for 3 hours. After addition of 0.1 g of sodium hydrogen carbonate, the mixture is concentrated to dryness under reduced pressure. The residue is extracted with 50 ml of ethyl acetate and the extract is concentrated to dryness. The residue is dissolved in 10 ml of ethyl acetate, and m-chloroperbenzoic acid (0.2 g) is added, followed by strirring for 50 hours. After addition of 0.2 ml of dimethyl sulfide, and the mixture is stirred further for 30 minutes and concentrated under reduced pressure. The residue is subjected to silica gel column chromatography (eluent: 60% ethyl acetate-40% n-hexane) to give trans i.e. (3S,4R)-4-acetoxy-3-[(R)-1-hydroxyethyl]-2-azetidinone (0.04 g).

1. concentrationthe mixture is concentrated to dryness under reduced pressure
2. extractionThe residue is extracted with 50 ml of ethyl acetate
3. concentrationthe extract is concentrated to dryness
4. dissolutionThe residue is dissolved in 10 ml of ethyl acetate
5. additionm-chloroperbenzoic acid (0.2 g) is added
6. waitby strirring for 50 hours
7. additionAfter addition of 0.2 ml of dimethyl sulfide
8. stirringthe mixture is stirred further for 30 minutes
9. concentrationconcentrated under reduced pressure