反应详情

In a 2 L round bottom flask charged with 600 mL of ethanol and NaBH4 (12.55 g, 0.33 mol, 1.1 eq.) at 0° C., ethyl hydroxy-(2-isopropoxytetrahydro-3-furanyl)acetate (70 g, 0.3 mol, 1 eq.) dissolved in 400 mL of ethanol was added dropwise over 1 hour at 0° C. The mixture was allowed to warm up at room temperature and stirred for 19 hours. After cooling at 0° C., diethanolamine hydrochloride (46.7 g, 0.33 mol, 1.1 eq.) dissolved in 100 mL of water was added over 10 min. and stirred for 8 hours. The solvent was evaporated under reduced pressure to afford a clear yellow solid. After dilution with 300 mL of ethylacetate, the heterogeneous mixture was filtered over dicalite. The mixture was used directly in the next step.

1. additionwas added dropwise over 1 hour at 0° C
2. temperatureAfter cooling at 0° C.
3. additionwas added over 10 min.
4. stirringstirred for 8 hours
5. customThe solvent was evaporated under reduced pressure
6. customto afford a clear yellow solid
7. filtrationAfter dilution with 300 mL of ethylacetate, the heterogeneous mixture was filtered over dicalite