反应详情

温度

50 °C

21 g of ethyl 8-hydroxy-2,6-dimethyl-octa-2,4,6-trien-1-oate in 500 ml of methylene chloride are stirred at -25° C. for 2 hours with 50 g of nickel peroxide (prepared in Example 1 and containing 6.1% of active oxygen). The mixture is then filtered, the solution evaporated to 100 ml, treated with 250 ml of n-hexane and again evaporated to 100 ml. The residual solution is cooled to 50° C., seeded with crystals of ethyl 2,6-dimethyl-8-oxo-octa-2,4,6-trien-1 -oate and left to crystallise for 30 minutes at 0° C. After filtration under suction and drying of the crystals, there are obtained 16.5 g (79.5%) of pure ethyl 2,6-dimethyl-8-oxo-octa-2,4,6-trien-1-oate.

1. filtrationThe mixture is then filtered
2. customthe solution evaporated to 100 ml
3. additiontreated with 250 ml of n-hexane
4. customagain evaporated to 100 ml
5. waitleft
6. customto crystallise for 30 minutes at 0° C
7. filtrationAfter filtration under suction
8. customdrying of the crystals, there