反应详情

温度

45 °C

To a suspension of magnesium turnings (1.4 g, 55.1 mmol) in anhydrous THF (6 mL) under nitrogen was slowly added a solution of (Z)-1-bromodec-4-ene 3 (11.5 g, 52.5 mmol) in THF (12 mL). The reaction mixture was stirred at 45° C. for 30 minutes under nitrogen. The solution was cooled to 0° C. and a solution of ethyl formate (4.1 g, 55.1 mmol) in THF (12 mL) was added dropwise to over 5 minutes. The solution was stirred at room temperature for 2 hours then cooled to −15° C. and quenched slowly with water (10 mL) followed by 5M hydrochloric acid (15 mL). Once the magnesium had completely dissolved, the solution was diluted with water (50 mL) and extracted with hexanes (3×75 mL). The combined extracts were dried on magnesium sulfate, filtered and concentrated in vacuo to dryness. The residue obtained was dissolved in ethanol (40 mL) and a solution of potassium hydroxide (4.4 g, 78.7 mmol)) in water (10 mL) was added. The reaction mixture was stirred vigorously for 30 minutes then concentrated in vacuo to remove ethanol. The solution was then made acidic with 5M hydrochloric acid (15 mL) and extracted with hexanes (3×75 mL). The combined hexanes extracts were dried on magnesium sulfate, filtered and concentrated in vacuo to dryness. The crude product was purified by column chromatography (100% hexanes to 2.5% ethyl acetate in hexanes) to afford (6Z,15Z)-henicosa-6,15-dien-11-ol 4 as a pale yellow oil (5.6 g, 35%). Rf 0.4 (10% EtOAc-Hexanes).

1. temperatureThe solution was cooled to 0° C.
2. stirringThe solution was stirred at room temperature for 2 hours
3. temperaturethen cooled to −15° C.
4. customquenched slowly with water (10 mL)
5. dissolutionOnce the magnesium had completely dissolved
6. additionthe solution was diluted with water (50 mL)
7. extractionextracted with hexanes (3×75 mL)
8. customThe combined extracts were dried on magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo to dryness
11. customThe residue obtained
12. stirringThe reaction mixture was stirred vigorously for 30 minutes
13. concentrationthen concentrated in vacuo
14. customto remove ethanol
15. extractionmade acidic with 5M hydrochloric acid (15 mL) and extracted with hexanes (3×75 mL)
16. dry with materialThe combined hexanes extracts were dried on magnesium sulfate
17. filtrationfiltered
18. concentrationconcentrated in vacuo to dryness
19. customThe crude product was purified by column chromatography (100% hexanes to 2.5% ethyl acetate in hexanes)