反应详情

A solution of (3S,4S)-4-(1-hydroxymethylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone (20 g) and imidazole (5.6 g) in dry dimethylformamide (45 ml) was treated with t-butyl dimethyl chlorosilane (6.77 g) at room temperature for 2 hours. The reaction mixture was diluted with cold water (200 ml) and ethyl acetate (150 ml). The aqueous layer was extracted with ethyl acetate (150 ml). The combined extracts were washed successively with 5% hydrochloric acid solution (80 ml×2) and brine (80 ml), and dried over anhydrous sodium sulfate. After filtration and concentration of the filtrate in vacuo, the concentrate was crystallized from isopropanol to give crystals of (3S,4S)-4-(1-t-butyldimethylsilyloxymethylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone. m.p., 90°-92° C.

1. extractionThe aqueous layer was extracted with ethyl acetate (150 ml)
2. washThe combined extracts were washed successively with 5% hydrochloric acid solution (80 ml×2) and brine (80 ml)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationAfter filtration and concentration of the filtrate in vacuo
5. customthe concentrate was crystallized from isopropanol