Bromide ion → (6Z,9Z)-18-bromooctadeca-6,9-diene

Temperature

45 °C

A 1 liter RBF was charged with magnesium turnings (11.1 g, 463 mmol), anhydrous THF (65 mL) and stir-bar and flushed with nitrogen. In a separate flask, a solution of linoleyl bromide (140 g, 425 mL) in anhydrous THF (150 mL) was prepared, and 20 mL of this solution added to the magnesium. When most of the heat had dissipated, the remainder of the bromide was added over a period of 15 minutes. Temperature was then maintained at 45° C. for 4 h. The reaction was then cooled (0° C.). Using a dropping funnel, a solution of ethyl formate (32.4 g, 438 mmol) in anhydrous THF (150 mL) was added over a 40 minute period. The reaction was stirred overnight at room temperature. The reaction was cooled to −15° C. and 5N HCl (185 mL) added slowly. The mixture was transferred to a 2 L separating funnel separated. Water (150 mL) and hexane (150 mL) were added, the mixture washed, and again the aqueous removed. The organic was washed a final time with water (150 mL) and then concentrated to a yellow oil. The yellow oil was stirred with a mixture of EtOH (210 mL), water (30 mL) and KOH (15.8 g) for 1.5 h at room temp. The EtOH was evaporated and the residue treated with hexane (50 mL). 5N HCl (200 mL) was added via dropping funnel. The organic was washed with water (2×50 mL) evaporated, dried and purified by chromatography (0-5% EtOAc in hexane, 91 g, 81%).

1. customflushed with nitrogen
2. temperatureThe reaction was then cooled (0° C.)
3. temperatureThe reaction was cooled to −15° C.
4. customseparating funnel
5. customseparated
6. additionWater (150 mL) and hexane (150 mL) were added
7. washthe mixture washed
8. washThe organic was washed a final time with water (150 mL)
9. concentrationconcentrated to a yellow oil
10. stirringThe yellow oil was stirred with a mixture of EtOH (210 mL), water (30 mL) and KOH (15.8 g) for 1.5 h at room temp
11. customThe EtOH was evaporated
12. additionthe residue treated with hexane (50 mL)
13. addition5N HCl (200 mL) was added
14. washThe organic was washed with water (2×50 mL)
15. customevaporated
16. customdried
17. custompurified by chromatography (0-5% EtOAc in hexane, 91 g, 81%)

ORD record

ord-b4f8570ca41c446e9e7bc977886895f4

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08865675B2