反应详情

To a solution of the product from Step E (8.89 g, 18.4 mmol) in methanol (200 mL)/methylene chloride (50 mL) at 0° C. was added sodium borohydride (695 mg, 18.4 mmol). After stirring for 1 hour, the reaction was quenched by the addition of sat. aq. NH4Cl until H2 evolution ceased. The solvents were removed in vacuo and the residue was partitioned between methylene chloride (200 mL) and water (200 mL). The layers were separated and the aqueous layer was washed with methylene chloride (3×50 mL). The combined organic layers were dried (NaSO4), filtered, and concentrated in vacuo to provide the title compound as a yellow oil which was sufficiently pure for use in the next step.

1. customthe reaction was quenched by the addition of sat. aq. NH4Cl until H2 evolution
2. customThe solvents were removed in vacuo
3. customthe residue was partitioned between methylene chloride (200 mL) and water (200 mL)
4. customThe layers were separated
5. washthe aqueous layer was washed with methylene chloride (3×50 mL)
6. dry with materialThe combined organic layers were dried (NaSO4)
7. filtrationfiltered
8. concentrationconcentrated in vacuo