反应详情

A solution of (R)-4-benzyl-3-(5-benzyloxypentanoyl)oxazolidin-2-one (132 g) in tetrahydrofuran (660 mL) was added dropwise to a mixture of sodium hexamethyldisilazane (1.9 M in tetrahydrofuran) (702 mL) and tetrahydrofuran (660 mL) at −78° C. The reaction temperature was rose to −40° C. To the mixture was added dropwise tert-butyl bromoacetate (85 mL) at −78° C. The reaction temperature was rose to −36° C. To the mixture was added dropwise N,N,N′-triethylethylenediamine (33 mL) at ice temperature. And then, to the mixture were added water (530 mL) and hexane (660 mL). The aqueous layer was removed, and the organic layer was washed with aqueous 20 w/v % citric acid (660 mL×3), water (660 mL), saturated aqueous sodium bicarbonate (660 mL) and brine (660 mL), then dried over magnesium sulfate. The magnesium sulfate was filtered off and the filtrate was concentrated in vacuo to give the title compound (196 g) as a crude product.

1. customto −40° C
2. customto −36° C
3. customThe aqueous layer was removed
4. washthe organic layer was washed with aqueous 20 w/v % citric acid (660 mL×3), water (660 mL), saturated aqueous sodium bicarbonate (660 mL) and brine (660 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationThe magnesium sulfate was filtered off
7. concentrationthe filtrate was concentrated in vacuo