反应详情

To a solution of the product from step D (0.36 g, 0.46 mmol) in tetrahydrofuran (5.0 mL) at 0° C. was added triphenylphosphine (0.36 g, 1.38 mmol), followed by dropwise addition of a solution of carbon tetrabromide (0.46 g, 1.38 mmol) in tetrahydrofuran (5.0 mL). The reaction mixture was allowed to warm to room temperature and stirred for 8 hours. The reaction solution was then quenched by addition of methanol and stirred for 15 minutes at room temperature. The resultant mixture was concentrated to dryness and the residue obtained was purified by flash column chromatography (eluent: hexanes/ethyl acetate 95:5 to 60:40) to give (2S,3R,4R,5R)-2-(3-(bromomethyl)-4-chlorophenyl)-3,4,5-tris(4-methoxybenzyloxy)-6-((4-methoxybenzyloxy)methyl)tetrahydro-2H-pyran (0.31 g, partial pure) as a light yellow oil, which was used in the next step without further purification.

1. customThe reaction solution was then quenched by addition of methanol
2. stirringstirred for 15 minutes at room temperature
3. concentrationThe resultant mixture was concentrated to dryness
4. customthe residue obtained
5. customwas purified by flash column chromatography (eluent: hexanes/ethyl acetate 95:5 to 60:40)