反应详情

To a solution of methyl 2-[(3R,4R)-3-amino-4-allyl-2-oxoazetidin-1-yl]-3-methylbut-2-enoate (500 mg) in dichloromethane (5 ml) was added acetic formic anhydride (0.34 ml) at 0°. After stirring at the same temperature for one hour, the mixture was diluted with ethyl acetate (35 ml) and washed with a dilute aqueous sodium bicarbonate. The aqueous layer was saturated with sodium chloride and extracted with dichloromethane. The extracts were combined, washed with a saturated aqueous sodium chloride, dried over magnesium sulfate and evaporated. The residue was chromatographed on silica gel (2.5 g) eluting with 10-30% acetone in dichloromethane afforded methyl 2-[(3R,4R)-3-formamido-4-allyl-2-oxoazetidin-1-yl]-3-methylbut-2-enoate (485 mg).

1. washwashed with a dilute aqueous sodium bicarbonate
2. extractionextracted with dichloromethane
3. washwashed with a saturated aqueous sodium chloride
4. dry with materialdried over magnesium sulfate
5. customevaporated
6. customThe residue was chromatographed on silica gel (2.5 g)
7. washeluting with 10-30% acetone in dichloromethane