Diethyl Ether → (E)-4-ethyl-2-hexen-1,4-diol

Temperatur

-70 °C

A 3 liter, round-bottom flask equipped with a mechanical stirrer, dropping funnel, thermometer and nitrogen bubbler was charged with 168 g of crude 4-ethyl-2-hexyn-1,4-diol TES-ether and 1 liter of THF. After cooling to −70° C. with a dry ice-acetone bath, 200 mL (600 mmol) 65+wt. % solution of Red-Al® in toluene was added slowly to control vigorous gas evolution and foaming during addition of the first 50% of the reagent. Then, the mixture was warmed to 0° C. with an ice bath and stirred for 1 hour. TLC analysis indicated complete reaction. The mixture was cooled to −70° C. and carefully quenched by the addition of 240 mL of 30% ammonium hydroxide solution, while maintaining the internal temperature below −50° C. The mixture was concentrated under reduced pressure to remove the THF and the resulting slurry was diluted with 400 mL of diethyl ether. The solid was removed by filtration and washed twice with 200 mL of diethyl ether. The combined filtrate and washes were washed twice with 200 mL of water and twice with 200 mL of saturated sodium chloride solution, dried over sodium sulfate and concentrated under reduced pressure, then under high vacuum to give 160 g of crude (E)-4-ethyl-2-hexen-1,4-diol TES-ether as a pale yellow viscous liquid. This material was used directly in the next step without further purification.

1. customA 3 liter, round-bottom flask equipped with a mechanical stirrer
2. temperatureThen, the mixture was warmed to 0° C. with an ice bath
3. customreaction
4. temperatureThe mixture was cooled to −70° C.
5. customcarefully quenched by the addition of 240 mL of 30% ammonium hydroxide solution
6. temperaturewhile maintaining the internal temperature below −50° C
7. concentrationThe mixture was concentrated under reduced pressure
8. customto remove the THF
9. additionthe resulting slurry was diluted with 400 mL of diethyl ether
10. customThe solid was removed by filtration
11. washwashed twice with 200 mL of diethyl ether
12. washThe combined filtrate and washes were washed twice with 200 mL of water and twice with 200 mL of saturated sodium chloride solution
13. dry with materialdried over sodium sulfate
14. concentrationconcentrated under reduced pressure

ORD-Eintrag

ord-6468a57feeb746cf9ec69c2f3f0dcd77

Quelldatensatz

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06255501B1