反应详情

In a 3-neck round bottom flask equipped with a stirring bar, a gas inlet tube and an addition funnel was added 20 ml of tetrahydrofuran, 50 ml of water and sodium bromide (0.20 mole). The solution was cooled to a temperature of 0° to 20° C. The addition funnel was charged with a solution of 1(2-furyl)-1-ethanol (0.18 mole) in 20 ml of tetrahydrofuran and this was added dropwise to the rapidly stirred reaction flask while gaseous chlorine (0.40 mole) is added via the gaseous inlet tube. The rate of the alcohol addition was such that a yellow orange color was maintained. The reaction temperature was kept below 20° C. with ice bath cooling. After the alcohol and chlorine had both been added to the reaction flask, the temperature was raised to reflux to distill off the tetrahydrofuran. The isolation procedure of Example 1 was used to isolate 12.47 g of pure maltol (55% yield).

1. customIn a 3-neck round bottom flask equipped with a stirring bar, a gas inlet tube and an addition funnel
2. temperatureThe solution was cooled to a temperature of 0° to 20° C
3. additionis added via the gaseous inlet tube
4. temperaturewas maintained
5. customThe reaction temperature was kept below 20° C. with ice bath
6. temperaturecooling
7. additionboth been added to the reaction flask
8. temperaturethe temperature was raised
9. temperatureto reflux
10. distillationto distill off the tetrahydrofuran