Reaktion #2146732

Reaktionsgleichung

1-isobutylcyclohex-1-ene

tin tetrachloride

crotonyl chloride

→

(E)-1-(2-isobutylcyclohex-2-enyl)but-2-en-1-one

Ausbeute 30.2%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe resulting mixture was stirred for 1 h at −70° C.
2. 2
   Waschenphase was first washed with concentrated NaOH
3. 3
   Trocknenwith H2O, dried (MgSO4)
4. 4
   Sonstigethe solvent evaporated
5. 5
   workup.DISTILLATIONShort-path Vigreux-distillation (0.15 mbar, bath temperature: 160° C.) of the crude product (592 g)
6. 6
   Sonstigegave a fraction (495 g, boiling range: 90-130° C.) that
7. 7
   workup.DISTILLATIONwas redistilled
8. 8
   Sonstigea short-path Vigreux-column (0.11 mbar, bath temperature: 160° C.)

Vorschrift

At −70° C., a solution of tin tetrachloride (533 ml, 4.54 mol, 1.4 eq.) in dichloromethane (2.5 l) was treated with crotonyl chloride (350 ml, 90%, 3.24 mol, 1.0 eq.). The resulting solution was stirred for 30 min. and treated within 1.5 h with a solution of 1-isobutylcyclohex-1-ene (448 g, 3.24 mol) in dichloromethane (400 ml). The resulting mixture was stirred for 1 h at −70° C. and poured into ice/H2O. The org. phase was first washed with concentrated NaOH then with H2O, dried (MgSO4), and the solvent evaporated. Short-path Vigreux-distillation (0.15 mbar, bath temperature: 160° C.) of the crude product (592 g) gave a fraction (495 g, boiling range: 90-130° C.) that was redistilled using again a short-path Vigreux-column (0.11 mbar, bath temperature: 160° C.) to give (E)-1-(2-isobutylcyclohex-2-enyl)but-2-en-1-one (202 g, 30%). Boiling point: 120° C. (0.11 mbar).

Quelle