反应详情

To a solution of (3R,4R)-3-(benzyloxycarbonylamino)-4-(2,2-dimethoxyethyl)azetidin-2-one (1.014 g) in tetrahydrofuran (15 ml) were added portionwise a solution of sodium cyanoborohydride (460 mg) in tetrahydrofuran (2.30 ml) and 2N hydrochloric acid (7.5 ml) at ambient temperature during a period of 90 minutes. The solution was adjusted to pH 7 with saturated aqueous sodium hydrogen carbonate and concentrated in vacuo. The concentrate was acidified to pH 4 with 2N hydrochloric acid, saturated with sodium chloride and extracted four times with chloroform. The combined extracts were dried over magnesium sulfate and evaporated in vacuo. The residue was chromatographed on silica gel (15 g, eluting with 3-10% methanol in dichloromethane) to give a crystalline solid, which was washed with ether and collected by filtration to give 553 mg of (3R,4R)-3-benzyloxycarbonylamino-4-(2-hydroxyethyl)azetidin-2-one.

1. concentrationconcentrated in vacuo
2. extractionextracted four times with chloroform
3. dry with materialThe combined extracts were dried over magnesium sulfate
4. customevaporated in vacuo
5. customThe residue was chromatographed on silica gel (15 g, eluting with 3-10% methanol in dichloromethane)
6. customto give a crystalline solid, which
7. washwas washed with ether
8. filtrationcollected by filtration