Bromine → Ethyl 2-(5-oxo-1-cyclopentenyl)acetate

HRID 839333Notes

Reaction equation

HRID 839333 reaction equation
C([O:4][C:5]1[CH2:9][CH2:8][CH2:7][C:6]=1[CH2:10][C:11]([O:13][CH2:14][CH3:15])=[O:12])(=O)C.BrBr.[Br-].[Li+].C(=O)([O-])[O-].[Li+].[Li+].Cl.NO.C([O-])(=O)C.[Na+]>CN(C)C=O.C(O)C.COCCO.CCCCCCC>[C:11]([CH2:10][C:6]1[C:5](=[O:4])[CH2:9][CH2:8][CH:7]=1)([O:13][CH2:14][CH3:15])=[O:12]

Participants

10

Reactant 5

HCID 24408BromineHCID 443297Hydroxyamine hydrochlorideHCID 517045Sodium AcetateHCID 203242041-Acetoxy-2-(carbethoxymethyl)cyclopent-1-eneHCID 86734010Trilithium;bromide;carbonate

Product 1

HCID 11355698Ethyl 2-(5-oxo-1-cyclopentenyl)acetate

Reagents, catalysts & solvents 4

HCID 702EthanolSolventHCID 6228DimethylformamideSolventHCID 80192-MethoxyethanolSolventHCID 8900HeptaneSolvent

Procedure

In the manner described in Example 13, treatment of 1-acetoxy-2-(carbethoxymethyl)cyclopent-1-ene (Example 211) with bromine and subsequent dehydrobromination with lithium bromide-lithium carbonate in N,N-dimethylformamide gives an amber oil. This material is subjected to chromatography on diatomaceous earth using an n-heptane:methyl cellosolve system. Removal of the solvent from hold back volume 4.5-4.7 gives an oil which is then further treated with hydroxylamine hydrochloride, sodium acetate in ethanol at room temperature for 18 hours to give the desired product; b.p. 71° C. (0.12 mm); λmaxMeOH 222 mμ (10,300); λ max 5.75, 5.85, 6.15, 8.65 μ.

Workup

  1. customgives an amber oil
  2. customRemoval of the solvent from hold back volume 4.5-4.7
  3. customgives an oil which

Sources & evidence

ORD record
ord-5dd3cb9eb50b4258941e202c82ae0e93
Source dataset
uspto-grants-1978_06
Patent number
US04094896

Reaction notes

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