Oxalic Acid → Cyclopentanecarboxylic acid, 1-fluoro-2-oxo-, ethyl ester

HRID 359901Notes

Reaction equation

HRID 359901 reaction equation
[H-].[Na+].[C:3]([CH:8]1[CH2:12][CH2:11][CH2:10][C:9]1=[O:13])([O:5][CH2:6][CH3:7])=[O:4].[F:14]N1CC2CCC(C2(C)C)(C)CS1(=O)=O.C(O)(=O)C(O)=O>O1CCCC1>[F:14][C:8]1([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH2:12][CH2:11][CH2:10][C:9]1=[O:13]

Participants

6

Reactant 4

HCID 971Oxalic AcidHCID 24758Sodium hydrideHCID 69136Ethyl 2-oxocyclopentanecarboxylateHCID 86744686HCID 86744686, compound

Product 1

HCID 10986766Cyclopentanecarboxylic acid, 1-fluoro-2-oxo-, ethyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a suspension of 1.56 mmol of sodium hydride in 5 ml of tetrahydrofuran are added, at 0° C., 1.3 mmol of 1-carboethoxycyclopentan-2-one and the mixture is stirred for 1 hour at 0° C. Then a solution of 1.4 mmol of (-)-N-fluorocamphor sultam (Example 4) is added dropwise, and stirring is continued for 3 hours at 0° C. The reaction mixture is then poured into 50 ml of 1M oxalic acid and extracted with diethyl ether. The organic phases are washed with 10% NaHCO3 solution and with a saturated solution of NaCl. The resultant mixture is purified over a column of silica gel, affording (+)-1-fluoro-1-carboethoxycyclopentan-2-one in high purity (ee=70%).

Workup

  1. additionare added, at 0° C.
  2. extractionextracted with diethyl ether
  3. washThe organic phases are washed with 10% NaHCO3 solution and with a saturated solution of NaCl
  4. customThe resultant mixture is purified over a column of silica gel

Sources & evidence

ORD record
ord-6b8439fae3324e8ca7f4f96d3580aba5
Source dataset
uspto-grants-1991_03
Patent number
US05003074

Reaction notes

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