反应详情

温度

20 °C

Compound 4b (50.0g, 228 mmol) along with 300 ml dichloromethane was charged into 2 liter round bottom flask. Crushed pyridinum dichromate (171.0 g, 456 mmol) and powdered molecular sieves (10 g) were both added into the flask. The heterogeneous reaction mixture was stirred for 16 hours at 20° C. The resulting reaction mixture was filtered through celite and washed with ether (500 ml×3). The combined filtrate was concentrated under reduced pressure. The crude product was eluted through a short silica gel pad (3 inches in length) withlo% EtOAc in hexane. The resulting product (42.0 g, yield=84%) was used for the following step.

1. additionboth added into the flask
2. customThe resulting reaction mixture
3. filtrationwas filtered through celite
4. washwashed with ether (500 ml×3)
5. concentrationThe combined filtrate was concentrated under reduced pressure
6. washThe crude product was eluted through a short silica gel pad (3 inches in length) withlo% EtOAc in hexane