Реакция #55255

Уравнение реакции

acetic acid water

(E)-1,1-dimethoxy-6,10-dimethyl-5,9-undecadien-2-one

sodium hydride

sodium borohydride

→

end product

(E,E,E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14-hexadecatetraenoic acid

Растворители

ethanol

dimethyl sulfoxide

water

ethyl ether

Условия реакции

Обработка

1. 1
   workup.STIRRINGThe resulting mixture was again stirred at 50°-55° C. for 30 minutes
2. 2
   ДругоеAfter completion of the reaction
3. 3
   Экстракцияthe reaction mixture was extracted four times with n-hexane
4. 4
   Промывкаthe extracts were washed with water
5. 5
   Сушкаdried over anhydrous sodium sulfate
6. 6
   workup.DISTILLATIONthe solvent was distilled off
7. 7
   Другоеto leave 10.4 g of an yellow oily substance
8. 8
   workup.STIRRINGat 5°-10° C. and the resulting mixture was stirred for 1 hour
9. 9
   workup.STIRRINGafter stirring
10. 10
    Другоеan aqueous layer was separated
11. 11
    Температураcooling
12. 12
    ДругоеThe so separated oily substance
13. 13
    Экстракцияwas extracted with ether
14. 14
    Промывкаthe extract was washed with water
15. 15
    Сушкаdried over anhydrous sodium sulfate
16. 16
    workup.DISTILLATIONThe solvent was distilled off

Методика

A suspension of 14.1 g of (E)-4-methyl-5-carboxy-4-penten-1-yltriphenylphosphonium bromide, 8.4 g of (E)-1,1-dimethoxy-6,10-dimethyl-5,9-undecadien-2-one and 2.5 g of 63.8% sodium hydride in 30 ml of anhydrous dimethyl sulfoxide was stirred at 50°-55° C. for 2.5 hours and 40 ml of acetic acid-water (5:1) was added thereto. The resulting mixture was again stirred at 50°-55° C. for 30 minutes. After completion of the reaction, the reaction mixture was extracted four times with n-hexane and the extracts were washed with water, dried over anhydrous sodium sulfate and then the solvent was distilled off to leave 10.4 g of an yellow oily substance. The resulting oil was dissolved in 50 ml of ethanol, 1.2 g of sodium borohydride was added thereto at 5°-10° C. and the resulting mixture was stirred for 1 hour. To the reaction mixture were added ethyl ether and water and, after stirring, an aqueous layer was separated and neutralized with hydrochloric acid under ice-cooling. The so separated oily substance was extracted with ether and the extract was washed with water and dried over anhydrous sodium sulfate. The solvent was distilled off to afford 3.98 g of the end product.

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