反应详情

温度

0 °C

(S)-methyloxazaborolidine (8.77 g, 31.63 mmol) dissolved in 30 mL of toluene. The solution was cooled to 0° C. and the borane tetrahydrofuran complex (31.6 mL of 1.0M solution in THF, 31.6 mmol) was added. After 30 min the ketone 24 (5.0 g, 31.63 mmol) was added. The reaction solution was stirred for 4 h and was then quenched by slow addition of saturated aqueous ammonium chloride. The resultant mixture was extracted with EtOAc (2×). The combined organic portions were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. Flash column chromatography (silica gel, 3:1 hex/EtOAc) afforded 2.58 g (51%) of the alcohol 25 (see scheme 4).

1. customwas then quenched by slow addition of saturated aqueous ammonium chloride
2. extractionThe resultant mixture was extracted with EtOAc (2×)
3. washThe combined organic portions were washed with brine
4. dry with materialdried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo