Reaction #44866

Reaction equation

CH2I2

methyl cyclopentanecarboxylate

HN(iPr)2

n-BuLi

→

title compound

Yield 52.0%

Methyl 1-(iodomethyl)cyclopentanecarboxylate

Yield 52.0%

Solvents

THF

THF

Conditions

Workup

1. 1
   Otherwith keeping −10° C. under N2
2. 2
   workup.STIRRINGthe mixture was stirred at 0° C. for 2 h
3. 3
   workup.STIRRINGthe resulting mixture was stirred at room temperature for 16 h
4. 4
   OtherThe reaction mixture was quenched with sat. NH4Cl aq. (50 mL)
5. 5
   Extractionextracted with Et2O (75 mL) for two times
6. 6
   Washthe combined organic layer was washed with brine (75 mL)
7. 7
   DryingThe organic layer was dried over Na2SO4
8. 8
   Filtrationfiltered
9. 9
   Concentrationconcentrated
10. 10
    OtherRemoval of the solvent
11. 11
    Othergave a residue, which
12. 12
    Otherwas chromatographed on a column of silica gel eluting with EtOAc/hexane (1:20→1:10)

Procedure

To a stirred solution of HN(iPr)2 (1.31 mL, 9.36 mmol) in THF (5 mL) was added n-BuLi (1.58 M in hexane, 5.43 mL, 8.58 mmol) with keeping −10° C. under N2, and the mixture was stirred at −10° C. for 1 h. Then, to this mixture was added a solution of methyl cyclopentanecarboxylate (1.00 g, 7.80 mmol) in THF (3 mL) dropwise at 0° C., and the mixture was stirred at 0° C. for 2 h. Finally, to this mixture was added CH2I2 (0.628 mL, 7.80 mmol) at 0° C., and the resulting mixture was stirred at room temperature for 16 h. The reaction mixture was quenched with sat. NH4Cl aq. (50 mL), extracted with Et2O (75 mL) for two times, and the combined organic layer was washed with brine (75 mL). The organic layer was dried over Na2SO4, filtered and concentrated. Removal of the solvent gave a residue, which was chromatographed on a column of silica gel eluting with EtOAc/hexane (1:20→1:10) to give 1.085 g (52%) of title compound as a colorless oil.

Source