反应详情

To a solution of (3S,4S)-3-[(1R)-1-benzyloxycarbonyloxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]-1-t-butoxycarbonylmethylazetidin-2-one (8.5 g) in 1,2-dichloroethane (185 ml), there was dropwise added a solution of boron tribromide (26.4 g) in 1,2-dichloroethane (100 ml) at -10° C. for 20 minutes, followed by stirring at the same temperature for 1 hour. Sodium bicarbonate (40 g) and ice-water (600 g) were added thereto while stirring, and the resultant mixture was diluted with ethyl acetate (200 ml). The aqueous layer was acidified with 2N hydrochloric acid (200 ml), extracted with ethyl acetate and combined with the organic layer. The combined organic layer was washed with brine (200 ml×3), dried over magnesium sulfate and evaporated in vacuo to give (3S,4S)-3-[(1R)-1-hydroxyethyl]-4-[(1R)-1-phenylthiocarbonylethyl]-1-carboxymethylazetidin-2-one (10.4 g, 87.9%.).,

1. stirringwhile stirring
2. extractionextracted with ethyl acetate
3. washThe combined organic layer was washed with brine (200 ml×3)
4. dry with materialdried over magnesium sulfate
5. customevaporated in vacuo