反应详情

温度

-10 °C

32.88 g (95.8%; 2.03 eq.) of [5-(4-hydroxy-2,6,6-trimethyl-1-cyclohexenyl)-3-methyl-2,4-pentadienyl]triphenylphosphonium chloride and 4.92 g (1 eq.) of 2,7-dimethyl-2,4,6-octatrien-1,8-dial (C10 -dial) in 490 ml of ethanol were placed in a 500 ml four-necked sulphonation flask equipped with an internal thermometer, stirrer and reflux condenser and cooled to -10° C. while stirring. A solution of 3.60 g of sodium hydroxide in 50 ml of ethanol was added dropwise to the resulting yellowish suspension at -10° C. while stirring and subsequently the reaction mixture was stirred at -10° C. for one hour. After heating to about 80° C. internal temperature within 30 minutes the product suspension was heated at reflux temperature during the following 17 hours. Subsequently, it was cooled to 0° C. and stirred for a further 1 hour, and the thus-obtained zeaxanthin was isolated by suction filtration. Then the filter cake was washed well with ethanol and subsequently freed from neutral salt with water.

1. customequipped with an internal thermometer, stirrer
2. temperaturereflux condenser
3. stirringwhile stirring
4. stirringsubsequently the reaction mixture was stirred at -10° C. for one hour
5. temperatureAfter heating to about 80° C. internal temperature within 30 minutes the product suspension
6. temperaturewas heated
7. temperatureat reflux temperature during the following 17 hours
8. temperatureSubsequently, it was cooled to 0° C.
9. stirringstirred for a further 1 hour