反应详情

A colorless solution of ethyl 2-methylpent-4-enoate (5.000 g; 35.16 mmol) in dioxane (260 ml) and water (85 ml) was treated successively with 2,6-lutidine (7.536 g; 70.32 mmol), a solution of osmium tetroxide (2.5 wt. % in 2-methylpropan-2-ol; 0.45 ml), and NaIO4 (30.083 g; 140.65 mmol). The resulting beige heterogeneous reaction mixture was further stirred at rt, under nitrogen, for 20.5 h. The resulting milky mixture was treated with water (100 ml) and DCM (500 ml). The layers were separated, and the aq. layer was further extracted with DCM (200 ml/150 ml). The mixed slightly yellow organic layers were then washed with brine (200 ml), dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure to give crude ethyl 2-methyl-4-oxobutanoate as a dark-yellow/slightly brown oil which was directly used for the next step without additional purification.

1. customThe resulting beige heterogeneous reaction mixture
2. customThe layers were separated
3. extractionthe aq. layer was further extracted with DCM (200 ml/150 ml)
4. additionThe mixed slightly yellow organic layers
5. washwere then washed with brine (200 ml)
6. dry with materialdried over anh. MgSO4
7. filtrationfiltered
8. concentrationconcentrated to dryness under reduced pressure