反应详情

温度

-45 °C

To a stirred −55° C. solution of (2S,3S,4R,5R,6R)-2-(2-(allyloxy)-4-chloro-5-(4-ethoxybenzyl)phenyl)-3,4,5-tris(benzyloxy)-6-(benzyloxymethyl)tetrahydro-2H-pyran (19, 8.54 g, 10 mmol) from Step 3 in acetic anhydride (50 mL)/dichloromethane (50 mL) was dropwise added trimethylsilyl trifluoromethanesulfonate (4.7 mL, 26 mmol) at a rate such that the reaction temperature was maintained between −50 and −55° C. The solution was allowed to warm to −45° C. over 1.5 h prior to quenching with saturated sodium hydrogen carbonate solution. The reaction mixture was extracted with dichloromethane and the combined organic layers were washed with saturated sodium hydrogen carbonate solution prior to drying over magnesium sulfate. After filtration and concentration under reduced pressure, the crude residue was purified on a Biotage® purification apparatus (silica gel, 5 to 20% tetrahydrofuran in hexanes gradient) to yield the title compound (20, 7.8 g, 10 mmol, 100%) as a white solid.

1. customTo a stirred −55° C.
2. temperaturewas maintained between −50 and −55° C
3. customto quenching with saturated sodium hydrogen carbonate solution
4. extractionThe reaction mixture was extracted with dichloromethane
5. washthe combined organic layers were washed with saturated sodium hydrogen carbonate solution
6. dry with materialto drying over magnesium sulfate
7. filtrationAfter filtration and concentration under reduced pressure
8. customthe crude residue was purified on a Biotage® purification apparatus (silica gel, 5 to 20% tetrahydrofuran in hexanes gradient)