反应详情

温度

23 °C

To a solution of alcohol 7 (400 mg, 2.32 mmol) in pyridine (pyridine was distilled over CaH2 and stored over KOH; 4.6 mL) at 23° C. was added acetic anhydride (1.10 mL, 11.6 mmol). The resulting mixture was stirred for 2 h at 23° C. The reaction was quenched by 1 N aqueous HCl (10 mL) at 0° C. and diluted with EtOAc (5 mL). The mixture was poured into a separatory funnel. The layers were separated and the aqueous layer was extracted with EtOAc (3×3 mL). The combined organic layers were washed with brine (5 mL), dried over Na2SO4, filtered, and concentrated in vacuo. Purification of the residue via flash chromatography (silica gel 40 mL; 5→30% EtOAc in hexanes) afforded acetate 8 (486 mg, 98%, 95% ee; the ee value was determined by HPLC((S,S) Whelk; 25 cm, 1.0 mL/min, hexanes/iPrOH=95/5).) as a colorless oil.

1. customThe reaction was quenched by 1 N aqueous HCl (10 mL) at 0° C.
2. additiondiluted with EtOAc (5 mL)
3. additionThe mixture was poured into a separatory funnel
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with EtOAc (3×3 mL)
6. washThe combined organic layers were washed with brine (5 mL)
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customPurification of the residue via flash chromatography (silica gel 40 mL; 5→30% EtOAc in hexanes)