反应详情

温度

80 °C

To a mixture of trans-2-hexenal (84.4 g; 0.86 mol) and acetic anhydride (102 g, 1 mol), 8 g (0.065 mol) of 4-dimethylaminopyridine and 105 g (1.04 mol) of triethylamine are added. The mixture is heated to 80° C. for two hours and then, after cooling at room temperature, 200 ml of chloroform is added. The organic layer is washed with two portions of 100 ml of ice-water and then with 30 ml of aqueous sodium bicarbonate. The chloroform layer is dried over MgSO4. Evaporation of the solvent under vacuum yields a residue which is distilled at 80° C./60 mmHg. Yield 106 g. N.M.R. and I.R. Spectrum confirm the assigned structure. The product is a mixture of four isomers containing more than 65% of the Δ-3,4-(E)-isomers.

1. additionare added
2. temperatureafter cooling at room temperature
3. washThe organic layer is washed with two portions of 100 ml of ice-water
4. dry with materialThe chloroform layer is dried over MgSO4
5. customEvaporation of the solvent under vacuum
6. customyields a residue which
7. distillationis distilled at 80° C./60 mmHg
8. additiona mixture of four isomers
9. additioncontaining more than 65% of the Δ-3,4-(E)-isomers