Tetrahydrofuran → Ethyl 4-(4-chlorophenyl)-4-methylpent-2-enoate

HRID 1506290Notes

Reaction equation

HRID 1506290 reaction equation
C[C:2]([CH3:5])([O-:4])C.[K+].[Cl:7][C:8]1[CH:13]=[CH:12][C:11]([C:14]([CH3:18])([CH3:17])[CH:15]=O)=[CH:10][CH:9]=1.C1C[O:22][CH2:21][CH2:20]1>>[Cl:7][C:8]1[CH:13]=[CH:12][C:11]([C:14]([CH3:18])([CH3:17])[CH:15]=[CH:20][C:21]([O:4][CH2:2][CH3:5])=[O:22])=[CH:10][CH:9]=1

Participants

4

Reactant 3

HCID 8028Tetrahydrofuran3×HCID 114353342-(4-Chlorophenyl)-2-methylpropanalHCID 23665647Potassium tert-butoxide

Product 1

HCID 67169239Ethyl 4-(4-chlorophenyl)-4-methylpent-2-enoateYield 44.5%

Procedure

To a stirring suspension of the triethyl phosphonoacetate (1.695 mL, 8.54 mmol) in 10 mL THF at 0° C. was added 1 M potassium tert-butoxide in THF (8.54 mL, 8.54 mmol). The resulting reddish orange solution was stirred for 30 min and then treated with a solution of the 2-(4-chlorophenyl)-2-methylpropanal (Intermediate I-9A, 0.78 g, 4.27 mmol) in 2.5 mL of THF and slowly warmed to room temperature. The reaction mixture was stirred at room temperature for 3 hrs and quenched with saturated. aq. ammonium chloride. The reaction mixture was partitioned between ethyl acetate and water. The organic layer was then washed with brine, dried over anhyd. magnesium sulfate, concentrated and chromatographed using silica gel flash chromatography to yield ethyl 4-(4-chlorophenyl)-4-methylpent-2-enoate (0.48 g, 1.899 mmol, 44.5% yield) as a clear oil. 1H NMR (400 MHz, CDCl3) δ ppm 7.28 (2H, d, J=8.79 Hz), 7.22 (2H, d, J=8.79 Hz), 7.08 (1H, d, J=16.26 Hz), 5.79 (1H, d, J=15.82 Hz), 4.20 (2H, q, J=7.03 Hz), 1.29 (3H, t, J=7.25 Hz).

Workup

  1. stirringThe reaction mixture was stirred at room temperature for 3 hrs
  2. customquenched with saturated
  3. customThe reaction mixture was partitioned between ethyl acetate and water
  4. washThe organic layer was then washed with brine
  5. customdried over anhyd
  6. concentrationmagnesium sulfate, concentrated
  7. customchromatographed

Sources & evidence

ORD record
ord-d05e3c2c9e2d45bbb34fd5fbcafc6204
Source dataset
uspto-grants-2015_12
Patent number
US09216972B2

Reaction notes

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