反应详情

(RS)-4-Chloroacetyltetrahydrofuran-2-one (2.060 g, 12.6 mmol), followed by potassium carbonate (0.690 g, 5 mmol) were added to crude t-butyl (2RS)-2-hydroxy-[(3R,4R)-4-mercapto-3-phenoxyacetamidoazetidin-2-on-1-yl]acetate (3.866 g) (prepared as described in Example 1c) in acetone (10 ml). The reaction was stirred 1 h. then diluted with ethyl acetate, washed with water (x2) and brine, dried, concentrated and flash chromatographed on silica gel eluting with 50,60,75,90% ethyl acetate in hexane to provide the title compound as a foam (3.458 g, 68%), νmax (CH2Cl2) 3380, 1780, 1680, 1235, 1150 cm-1 ; [Mass spectrum: +ve ion (thioglycerol) MH+ (509)].

1. washwashed with water (x2) and brine
2. customdried
3. concentrationconcentrated
4. customflash chromatographed on silica gel eluting with 50,60,75,90% ethyl acetate in hexane