反应详情

(R)—N-Propylnorvalinol (11.53 g) was dissolved in dichloromethane (160 mL), and N-methylmorpholine (21.8 mL) was added thereto under stirring at room temperature. A solution of thionyl chloride (6.9 mL) in dichloromethane (48 mL) was added dropwise to the resulting solution over 120 minutes under stirring at 2° C. The resulting suspension was stirred at room temperature for 4 hours. Water (104 mL) was added to the suspension under stirring at 3° C. The mixture was separated and the organic layer was washed with an aqueous 1 mol/L hydrochloric acid solution (104 mL) and subsequently with a saturated aqueous sodium hydrogen carbonate solution (104 mL), dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was dried under reduced pressure at room temperature for 19 hours to give (R)-3,4-dipropyl-1,2,3-oxathiazolidine 2-oxide as a red oil (12.36 g, 81% yield, cis:trans=about 45:55 determined from the integration ratio in 1H-NMR).

1. stirringunder stirring at 2° C
2. stirringThe resulting suspension was stirred at room temperature for 4 hours
3. stirringunder stirring at 3° C
4. customThe mixture was separated
5. washthe organic layer was washed with an aqueous 1 mol/L hydrochloric acid solution (104 mL) and subsequently with a saturated aqueous sodium hydrogen carbonate solution (104 mL)
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated under reduced pressure
8. customThe residue was dried under reduced pressure at room temperature for 19 hours