反应详情

Sodium hydride (ca. 60%, 1.0 g, 28.1 mmol) was dissolved in tetrahydrofuran (10 ml), and a solution of diethyl cyanomethylphosphonate (4.7 g, 26.8 mmol) in tetrahydrofuran (5 ml) was added under ice cooling condition. The mixture was stirred for 1 hr. Successively, a solution of 2-pyridinecarbaldehyde (2.7 g, 25.0 mmol) in tetrahydrofuran (5 ml) was added to the mixture, and the mixture was stirred at 0° C. to room temperature for 3 hrs. The reaction mixture was combined with water under ice cooling condition, concentrated under reduced pressure to the half amount and extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over magnesium sulfate. The solvent was evaporated, and the residue was subjected to a silica gel (100 g) column chromatography. The fractions eluted with hexane-ethyl acetate (2:1, v/v) were collected and concentrated to give the titled compound (a mixture of E-form and Z-form, 2.5 g, 77%).

1. stirringthe mixture was stirred at 0° C. to room temperature for 3 hrs
2. concentrationconcentrated under reduced pressure to the half amount
3. extractionextracted with ethyl acetate
4. washThe organic layer was washed with saturated brine
5. dry with materialdried over magnesium sulfate
6. customThe solvent was evaporated
7. washThe fractions eluted with hexane-ethyl acetate (2:1
8. customv/v) were collected
9. concentrationconcentrated