Reaktion #490351

Reaktionsgleichung

2,2-dimethyl-4-pentenal

Butyllithium

ammonium chloride

→

4,4-dimethyl-non-1-en-5-ol

Ausbeute 100.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeflushed with N2
2. 2
   Sonstigesealed with rubber stoppers
3. 3
   workup.ADDITIONThe reaction temperature was kept at −65° C., during addition
4. 4
   Temperaturto warm to −5° C. over 1 hour
5. 5
   Temperaturcooled to −60° C. again
6. 6
   SonstigeTHF was evaporated
7. 7
   Sonstigea rotary evaporator
8. 8
   Sonstigeset at 30° C
9. 9
   ExtraktionThe resultant aqueous solution was first extracted with CH2Cl2 (3×200 mL)
10. 10
    Sonstigedried
11. 11
    Einengenconcentrated on a rotary evaporator (30° C. water bath)

Vorschrift

15 g (133 mmol) of 2,2-dimethyl-4-pentenal was added to 600 mL of THF in a 2 L, 3-neck flask, flushed with N2, and sealed with rubber stoppers. The reaction mixture was cooled to 60° C. in a dry ice/acetone bath. Butyllithium solution (2.5 M in hexane, 64.4 mL, 160.7 mmol) was added 4-5 mL at a time from a 20 mL glass syringe. The reaction temperature was kept at −65° C., during addition and afterwards was stirred for an additional hour. The reaction mixture was allowed to warm to −5° C. over 1 hour, cooled to −60° C. again, and slowly quenched with ammonium chloride solution (10.5 g/200 mL water, 200 mmol). THF was evaporated using a rotary evaporator, keeping the water bath temperature set at 30° C. The resultant aqueous solution was first extracted with CH2Cl2 (3×200 mL), and then with ether (1×200 mL). The organic extracts were combined, dried, and concentrated on a rotary evaporator (30° C. water bath) to yield 22.64 g of 4,4-dimethyl-non-1-en-5-ol, TLC Rf=0.67 (1:1 ethyl acetate:hexanes, visualization by I2). 1H NMR (CDCl3, 500 MHz) δ (ppm): 5.86 (m, 1H), 5.06 (m, 1H)), 5.03 (s, 1H), 3.26 (d, 1H), 2.15 (m, 1H), 1.95 (m, 1H), 1.5 (m, 2H), 1.3 (m, 4H), 0.95, (t, 3H), 0.90 (s, 3H), 0.89 (s, 3H).

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