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] (2.0 g, 3.5 mmol) in toluene (60 mL) at room temperature. The mixture was stirred for 3 hour at the same temperature. Methanol (50 mL) was added dropwise to the stirred mixture at −5-+5° C. and the cooling bath was removed. The mixture was stirred for 1 hours at room temperature, filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (hexane/ethyl acetate 1:5 v/v) to obtain 1.0 g (73% yield) of the compound [12a]. 1H and 13C NMR are in agreement with the structure.

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. customThe residue was purified by column chromatography on silica gel (hexane/ethyl acetate 1:5 v/v)