Acetaldehyde → HCID 18353311, compound

Participants

Reaction Steps

To a stirred solution of borane dimethyl sulphide complex (1.42 ml, 15 mmol) in THF at 0° was added dropwise α-pinene (5 ml, 31.5 mmol). The reaction mixture was stirred at room temperature for 30 min. The reaction mixture was cooled to −35° and ethyl propionate (1.47 g, 1.52 ml, 15 mmol) added dropwise. The reaction mixture was stirred at room temperature for 2 h and then cooled to 0°. Acetaldehyde (5 ml, 3.94 g, 89 mmol) was added dropwise. The reaction mixture was heated to reflux for 1 h. Upon cooling the solvent and volatiles were removed by evaporation in vacuo. The residue was dissolved in THF (50 ml) and pinacol (1.8 g, 18 mmol) added. The reaction mixture was stirred for 1 h at room temperature. The solvent and volatiles were removed by evaporation in vacuo. To the crude product was added 2,4-dichloropyrimidine (2.24 g, 15 mmol) followed by cesium fluoride (4.56 g, 30 mmol) and tetrakis(triphenylphosphine)palladium (0) (0.88 g, 0.75 mmol). The reaction mixture was diluted with dioxane (50 ml) and heated under reflux for 3 h. Upon cooling the reaction mixture was poured into saturated sodium hydrogen carbonate solution (100 ml) and extracted twice with dichloromethane (100 ml). The combined organic fractions were dried over magnesium sulphate, filtered and the solvent removed by evaporation in vacuo. Purification by flash column chromatography (diisopropylethersilica) gave the title compound (1.59 g, 50%). 1H NMR (CDCl3) δ 6.78 (1H, d, J 12 Hz), 6.62 (1H, d, J 12 Hz), 4.22 (2H, q, J 8 Hz) and 1.21 (3H, t, J 8 Hz).

Provenance & Evidence