Reaktion #65055

Reaktionsgleichung

3-acetyl-5-methyldihydro-2(3H)-furanone

sodium hydroxide

cyclohexanecarboxaldehyde

→

3-cyclohexylmethylene-5-methyldihydro-2(3H)-furanone

Ausbeute 97.8%

Lösungsmittel

propionaldehyde diethyl acetal

propionaldehyde diethyl acetal

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefor the reaction
2. 2
   workup.ADDITIONadded
3. 3
   workup.STIRRINGto stir for 10 minutes
4. 4
   Temperaturheated
5. 5
   workup.ADDITIONwas added over a one-hour period
6. 6
   TemperaturThe mixture was heated
7. 7
   Temperaturunder reflux for an additional twelve hours
8. 8
   Temperaturcooled

Vorschrift

Example I was repeated using propionaldehyde diethyl acetal as the azeotroping solvent for the reaction. For the reaction 100 ml propionaldehyde diethyl acetal was charged to the reactor with 14.9 g (0.10 mole) 3-acetyl-5-methyldihydro-2(3H)-furanone. The mixture was stirred and 4 g (0.10 mole) powdered sodium hydroxide added. The mixture was allowed to stir for 10 minutes and then heated to reflux for 51/2 hours after which time 14.0 g (0.125 mole) cyclohexanecarboxaldehyde was added over a one-hour period. The mixture was heated under reflux for an additional twelve hours, cooled and worked up to recover 19 g crude 3-cyclohexylmethylene-5-methyldihydro-2(3H)-furanone (59% yield). The structure of the product was confirmed by proton and carbon nuclear magnetic resonance spectroscopy.

Quelle