Reaction #1994246

Reaction equation

2-allylpent-4-enoic acid ethyl ester

sodium hydroxide

→

2-allylpent-4-enoic acid

Yield 54.2%

Solvents

methanol

water

Conditions

Workup

1. 1
   Temperatureheated
2. 2
   Temperatureat reflux temperature for 2 hours
3. 3
   Othersolvent was removed at reduced pressure
4. 4
   workup.ADDITIONTo the residue were added 75 mL of diethyl ether and 10 mL of concentrated hydrochloric acid
5. 5
   workup.STIRRINGThe mixture was stirred at room temperature for 10 minutes
6. 6
   Otherthe layers were separated
7. 7
   Dryingthe diethyl ether layer was dried over magnesium sulfate
8. 8
   FiltrationAfter filtration
9. 9
   Otherto remove the magnesium sulfate, solvent
10. 10
    Otherwas removed at reduced pressure

Procedure

To a stirred solution of 2-allylpent-4-enoic acid ethyl ester (prepared above, 9.0 g, 54 mmol) in 50 mL of methanol and 2 mL of water was added sodium hydroxide (2.5 g, 63 mmol, available from EMD). The solution was stirred for 15 hours, then heated at reflux temperature for 2 hours. After cooling the reaction mixture to room temperature, solvent was removed at reduced pressure. To the residue were added 75 mL of diethyl ether and 10 mL of concentrated hydrochloric acid. The mixture was stirred at room temperature for 10 minutes, then the layers were separated and the diethyl ether layer was dried over magnesium sulfate. After filtration to remove the magnesium sulfate, solvent was removed at reduced pressure to leave 4.1 g of 2-allylpent-4-enoic acid as a colorless oil whose structure was confirmed by NMR analyses.

Source