Benzyl 2,2,2-trichloroacetimidate → methyl(2S)-2-benzoxy-4-methylpentanoate

HRID 861312Notes

Reaction equation

HRID 861312 reaction equation
[OH:1][C@@H:2]([CH2:7][CH:8]([CH3:10])[CH3:9])[C:3]([O:5][CH3:6])=[O:4].ClC(Cl)(Cl)C(=N)O[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>C(Cl)Cl>[CH2:15]([O:1][C@@H:2]([CH2:7][CH:8]([CH3:10])[CH3:9])[C:3]([O:5][CH3:6])=[O:4])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

4

Reactant 2

HCID 144968Benzyl 2,2,2-trichloroacetimidateHCID 9989388Methyl (2S)-2-hydroxy-4-methylpentanoate

Product 1

HCID 57145336methyl(2S)-2-benzoxy-4-methylpentanoateYield 74.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of methyl (2S)-2-hydroxy-4-methylpentanoate (0.5 g, 3.4 mmol) in anhydrous CH2Cl2 (10 mL) at R.T. under Ar was added benzyl 2,2,2-trichloroacetimidate (1.4 mL, 6.8 mmol) and trifluoromethylsulfonyl acid (25 μl). After 30 min the reaction mixture was taken up in CH2Cl2 (20 mL). The organic layer was washed with sat. NaCl (2×10 mL), 1N HCl (2×10 mL), sat. NaCl (2×10 mL), dried (MgSO4), filtered and concentrated. Purification by flash chromatography on silica gel (EA:H; 1:10) afforded methyl (2S)-2-benzoxy-4-methylpentanoate as an oil (0.6 g, 73.5%): 1 H NMR (CDCl3, 300 MHz) δ 0.80-0.98 (m, 6H), 1.40-1.58 (m, 1H), 1.69-1.87 (m, 2H), 3.74 (s, 3H), 3.93-4.06 (m, 1H), 4.42 (d, 1H, J=12.0 Hz), 4.68-4.80 (m, 1H), 7.14-7.32 (m, 5H) ppm.

Workup

  1. washThe organic layer was washed with sat. NaCl (2×10 mL), 1N HCl (2×10 mL), sat. NaCl (2×10 mL)
  2. dry with materialdried (MgSO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customPurification by flash chromatography on silica gel (EA:H; 1:10)

Sources & evidence

ORD record
ord-0e3d9e63b9b840bea35f6560d0de3502
Source dataset
uspto-grants-1998_02
Patent number
US05714471

Reaction notes

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