反应详情

A solution of ethyl 3-(dimethoxymethyl)-crotonate (73 g) in ethyl acetate (200 ml) was hydrogenated at 50 psi for 3 h in the presence of 10% palladium on charcoal (7 g). The solution was filtered, evaporated, and the residual oil treated with 0.25 M hydrogen chloride in 75% aqueous methanol for 2 h. To the reaction mixture was added ethyl acetate (300 ml) and water (150 ml). The organic phase was successively washed with sat. sodium bicarbonate solution (3×150 ml), water (100 ml) and dried over magnesium sulfate. The solution was concentrated in vacuo and the residual oil purified by chromatography on silica gel eluting with ethyl acetate-hexane (1:9) to give ethyl 3-formylbutyrate (26.5 g, 48%).

1. filtrationThe solution was filtered
2. customevaporated
3. additionthe residual oil treated with 0.25 M hydrogen chloride in 75% aqueous methanol for 2 h
4. additionTo the reaction mixture was added ethyl acetate (300 ml) and water (150 ml)
5. washThe organic phase was successively washed with sat. sodium bicarbonate solution (3×150 ml), water (100 ml)
6. dry with materialdried over magnesium sulfate
7. concentrationThe solution was concentrated in vacuo
8. customthe residual oil purified by chromatography on silica gel eluting with ethyl acetate-hexane (1:9)