Sodium Carbonate → 3-Ethyl-2-methoxy-2-cyclopenten-1-one

Reaction equation

[CH3:1][O:2][CH2:3][C:4](=[O:15])[CH:5]([CH2:10][C:11](=O)[CH2:12][CH3:13])C(OC)=O.C([O-])([O-])=O.[Na+].[Na+]>>[CH2:12]([C:11]1[CH2:10][CH2:5][C:4](=[O:15])[C:3]=1[O:2][CH3:1])[CH3:13]

Participants

Reactant 2

HCID 10340Sodium Carbonate

HCID 19871666Methyl 4-methoxy-2-(2-oxobutyl)-acetoacetate

Product 1

HCID 115573013-Ethyl-2-methoxy-2-cyclopenten-1-oneYield 29.1%

Procedure

21.60 g(100 mmol) of methyl 4-methoxy-2-(2-oxobutyl)-acetoacetate are held at reflux temperature for 8 hours with 212.0 g (50 mmol) of 2.5% Na2CO3 solution. After cooling the reaction mixture is extracted 3 times with 200 ml of CH2Cl2 each time. The combined organic phases are dried over magnesium sulphate and concentrated on a rotary evaporator. The crude product is column chromatographed over SiO2 and gives 4.08 g (29.1%) of 3-ethyl-2-methoxy-2-cyclopenten-1-one.

Workup

temperatureAfter cooling the reaction mixture
extractionis extracted 3 times with 200 ml of CH2Cl2 each time
dry with materialThe combined organic phases are dried over magnesium sulphate
concentrationconcentrated on a rotary evaporator
customchromatographed over SiO2

Sources & evidence

ORD record: ord-b8a97ca758a54388b57a2fd160ffb0f9
Source dataset: uspto-grants-1990_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04892966

Reaction notes

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