反应详情

m-Chloroperbenzoic acid (1.00 mmol) is added to a solution of (3S,4R)-1-(t-butyldimethylsilyl-3-[(R)-1-hydroxyethyl]-4-(2-oxo-2-trimethylsilylethyl)azetidin-2-one (1.00 mmol) in chloroform (4 ml). The resulting solution is heated at reflux for 4 hr, then cooled, concentrated in vacuo, and the residue chromatographed on silica gel (2% glacial acetic acid in methylene chloride). (3S,4R)-1-(t-butyldimethylsilyl)-3-[(R)-1-hydroxyethyl]-4-carboxymethyl-azetidin-2-one, 238 mg (83%) is isolated as a colorless solid, Rf =0.25. n.m.r. (CDCl3 & D2O) δ 3.6-4.3 (2H, m, H-5, H-8), δ 2.98 (1H, dd, J=7, 2.1H-6), δ 2.7 (2H,d of ABq)-CH2CO2H), δ 1.29 (3H, d, J=6, CH3 --) δ 0.95 (9H, S, Si±), δ 0.25 (6H, S, (CH3)2 -Si).

1. temperatureThe resulting solution is heated
2. temperatureat reflux for 4 hr
3. temperaturecooled
4. concentrationconcentrated in vacuo
5. customthe residue chromatographed on silica gel (2% glacial acetic acid in methylene chloride)