反应详情

After triphenylphosphine (4.72 g, 18.0 mmol) was added to a solution of (±)-2-(2-hydroxyethyl)-N-methyl-N-(4-phenoxybenzenesulfonyl)glycine allyl ester (6.08 g, 15.0 mmol), the product of Example 41(2), in tetrahydrofuran (45 ml), a solution of carbon tetrabromide (5.97 g, 18.0 mmol) in tetrahydrofuran (20 ml) was added over 20 minutes to the solution with ice-cooling and with stirring. The mixture was stirred at room temperature for 1 hour. To the reaction mixture, water was added and this was extracted with ethyl acetate. The organic layer was washed with water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using hexane/ethyl acetate=5/1 as the eluant to afford the desired compound (6.05 g, yield 86%) as a colorless oil.

1. temperaturecooling
2. stirringThe mixture was stirred at room temperature for 1 hour
3. extractionthis was extracted with ethyl acetate
4. washThe organic layer was washed with water
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by chromatography on a silica gel column