Ethyl 2-ethyl-4-oxocyclopent-2-enecarboxylate → Cyclopentanecarboxylic acid, 2-ethyl-4-oxo-, ethyl ester
Reaction equation
[CH2:1]([C:3]1[CH:4]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:5][C:6](=[O:8])[CH:7]=1)[CH3:2]>[Pd].CCOC(C)=O>[CH2:1]([CH:3]1[CH2:7][C:6](=[O:8])[CH2:5][CH:4]1[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH3:2]Participants
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 0 °C
Procedure
A round-bottom flask was charged with 10% palladium on carbon (10 g, 9.4 mmol). The flask was cooled to about 0° C. and EtOAc (400 mL) was added under a nitrogen atmosphere. The cooling bath was removed and ethyl 2-ethyl-4-oxocyclopent-2-enecarboxylate (47.8 g, 263 mmol) was added. Hydrogen gas was bubbled through the mixture for about 5 min and the mixture was then stirred under a hydrogen atmosphere for about 48 h at ambient temperature. The hydrogen source was removed, the mixture was bubbled with nitrogen for about 5 min and was filtered through a pad of Celite®. The filter cake was rinsed with EtOAc (400 mL). The filtrate was concentrated under reduced pressure to give ethyl 2-ethyl-4-oxocyclopentanecarboxylate (about 9:1 mixture cis:trans) (48.0 g, 99%) as a yellow liquid: 1H NMR (CDCl3) δ 4.23-4.10 (m, 2H), 3.22 (m, 1H), 2.59-2.50 (m, 1H), 2.44-2.28 (m, 3H), 2.26-2.16 (m, 1H), 1.58-1.46 (m, 1H), 1.41-1.30 (m, 1H), 1.30-1.23 (m, 3H), 1.02-0.91 (m, 3H).
Workup
- customThe cooling bath was removed
- customHydrogen gas was bubbled through the mixture for about 5 min
- customThe hydrogen source was removed
- customthe mixture was bubbled with nitrogen for about 5 min
- filtrationwas filtered through a pad of Celite®
- washThe filter cake was rinsed with EtOAc (400 mL)
- concentrationThe filtrate was concentrated under reduced pressure
Sources & evidence
- ORD record
- ord-914e02c89540422bacbfbb97e8526c84
- Source dataset
- uspto-grants-2016_06
- Patent number
- US09365579B2
Reaction notes
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