Reaktion #1463479

Reaktionsgleichung

2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide

tetrahydrofuran

tetrahydrofuran

4-(3,4,5-trifluorophenyl)cyclohexanone

potassium t-butoxide

→

1-(2-(1,3-dioxan-2-yl)-ethylidene)-4-(3,4,5-trifluorophenyl)cyclohexane

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeInto a three-necked flask equipped with a dropping fumel
2. 2
   Sonstigereached 10° C.
3. 3
   Sonstigeup to room temperature
4. 4
   Sonstigefor one hour
5. 5
   workup.STIRRINGstirring for one hour
6. 6
   workup.STIRRINGfurther stirring the reaction mixture for 5 hours
7. 7
   workup.ADDITIONafter completion of the dropwise addition
8. 8
   Filtrationfiltering off
9. 9
   Einengenconcentrating the filtrate under reduced pressure
10. 10
    Sonstigeisolating
11. 11
    Sonstigepurifying the resulting pale brown oil by means of silica gel column chromatography

Vorschrift

Into a three-necked flask equipped with a dropping fumel, a three-way cock and a thermometer was placed 2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide (12.2 g, 27 mole), followed by adding tetrahydrofuran (200 ml), suspending it, stirring under ice cooling till the liquid temperature reached 10° C., adding potassium t-butoxide (3.0 g, 27 mmols) to the reaction mixture, further elevating the temperature up to room temperature under ice cooling for one hour, stirring for one hour, dropwise adding a tetrahydrofuran (50 ml) solution of 4-(3,4,5-trifluorophenyl)cyclohexanone (5.7 g, 25 mmols) from the dropping funnel over 30 minutes, further stirring the reaction mixture for 5 hours after completion of the dropwise addition, adding ether (100 ml), allowing to stand for one hour, filtering off deposited insoluble substance, concentrating the filtrate under reduced pressure and isolating and purifying the resulting pale brown oil by means of silica gel column chromatography, to obtain 1-(2-(1,3-dioxan-2-yl)-ethylidene)-4-(3,4,5-trifluorophenyl)cyclohexane.

Quelle