反应详情

温度

-20 °C

To a suspension of 30.3 g. of sodium ethoxide in 300 ml. of tetrahydrofuran was added 118 g. of diethyl 3-ethoxycarbonyl-2-methyl-2-propenylphosphonate. To the mixture was added 67 g. of 3,7,11-trimethyl-2,4,6,10-dodecatetraene-1-al under stirring, chilling with ice and shielding from the light. After 1 hour, the reaction liquid was poured into 1 liter of water, and 1 liter of n-hexane was added for extraction. The n-hexane phase was separated, washed with two 100 ml. portions of a mixture of methanol and water (2:1), and concentrated to give 99 g. of a concentrate. To a refluxing solution of 8.2 g. of potassium hydroxide and 80 ml. of isopropyl alcohol was added 21 g. of the concentrate under shielding from the light. After 15 minutes, the reaction liquid was poured into 300 ml. of ice-water, made acidic by addition of hydrochloric acid, and extracted with 300 ml. of diethyl ether. The extract was washed with three 100 ml. portions of water, dried over magnesium sulfate, and evaporated to remove the solvent. The residue was dissolved in 200 ml. of n-hexane and chilled to -20° C. to crystallize it. There was obtained 9.8 g. of the desired product as pale yellow crystals.

1. additionTo a suspension of 30.3 g
2. additionTo the mixture was added 67 g
3. temperaturechilling with ice and shielding from the light
4. customthe reaction liquid
5. additionwas added for extraction
6. customThe n-hexane phase was separated
7. washwashed with two 100 ml
8. additionportions of a mixture of methanol and water (2:1)
9. concentrationconcentrated
10. customto give 99 g
11. concentrationof the concentrate
12. waitAfter 15 minutes
13. customthe reaction liquid
14. additionwas poured into 300 ml
15. extractionextracted with 300 ml
16. washThe extract was washed with three 100 ml
17. dry with materialportions of water, dried over magnesium sulfate
18. customevaporated
19. customto remove the solvent
20. dissolutionThe residue was dissolved in 200 ml
21. customto crystallize it
22. customThere was obtained 9.8 g