反应详情

To a solution of ((2R,3R,4R,5S,6S)-6-(2-(allyloxy)-4-chloro-5-(4-ethoxybenzyl)phenyl)-3,4,5-tris(benzyloxy)tetrahydro-2H-pyran-2-yl)methyl acetate (20, 7.8 g, 10 mmol) from Step 4 in methanol (130 mL) was added sodium methoxide (25% in methanol, 13 mL) and the reaction mixture was vigorously stirred at ambient temperature for 5 h. The solution was cooled to 0° C. prior to neutralizing with acetic acid (6.5 mL). After removal of organic volatiles under reduced pressure, the residue was diluted ethyl acetate and water. The organic layer was separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with sodium hydrogen carbonate and brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The crude residue was purified on Biotage® purification apparatus (silica gel, 5 to 30% tetrahydrofuran in hexanes) to yield the title compound (21, 7.2 g, 9.8 mmol, 98%) as a white solid.

1. temperatureThe solution was cooled to 0° C.
2. customAfter removal of organic volatiles under reduced pressure
3. customThe organic layer was separated
4. extractionthe aqueous layer was extracted with ethyl acetate
5. washThe combined organic layers were washed with sodium hydrogen carbonate and brine
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe crude residue was purified on Biotage® purification apparatus (silica gel, 5 to 30% tetrahydrofuran in hexanes)