反应详情

A 1.5 M solution of Diisobutylaluminum hydride in toluene (12.6 mL, 18.9 mmol) was added dropwise to a stirred solution of a compound [9a] (4.1 g, 7.2 mmol) in toluene (60 mL) at −70-−80° C. (acetone/dry ice bath). The mixture was stirred for 1 hour at the same temperature. Methanol (50 mL) was added dropwise to the stirred mixture at −70-−80° C. and the cooling bath was removed. The mixture was stirred for 1 hours at room temperature, filtered and evaporated under reduced pressure. A solution of the residue in dichloromethane (150 mL) was washed with brine (2×10 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (hexane/ethyl acetate 1:2 v/v) to obtain compound [11a] (2.53 g, 90% yield).

1. customthe cooling bath was removed
2. stirringThe mixture was stirred for 1 hours at room temperature
3. filtrationfiltered
4. customevaporated under reduced pressure
5. washA solution of the residue in dichloromethane (150 mL) was washed with brine (2×10 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. customevaporated under reduced pressure
9. customThe residue was purified by column chromatography on silica gel (hexane/ethyl acetate 1:2 v/v)