benzyl 2,2,2-trichloroethanimidate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl (S)-(+)-3-hydroxybutyrate (17) (2.223 g, 18.82 mmol) and benzyl 2,2,2-trichloroacetimidate (4.2 mL) were dissolved into 37.5 mL of cyclohexane/methylene chloride (2:1). After the addition of 0.2 mL of trifluoromethane sulfonic acid the reaction was stirred under nitrogen for one hour. The reaction was diluted with 75 mL of cyclohexane/methylene chloride (2:1) and filtered. The organic layer was washed with 50 mL of saturated sodium bicarbonate and 50 mL of distilled water. After drying with anhydrous sodium sulfate the solution was filtered and the solvents were removed on a rotovap. The resulting solid was purified using silica gel and elution with ether/hexane (1:4). filtered The organic layer was washed with 50 mL of saturated sodium bicarbonate and 50 mL of distilled water After drying with anhydrous sodium sulfate the solution was filtered the solvents were removed on a rotovap The resulting solid was purified silica gel and elution with ether/hexane (1:4)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

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 trifluoromethylsulfonic 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%): 1H 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. The organic layer was washed with sat. NaCl (2×10 mL), 1N HCl (2×10 mL), sat. NaCl (2×10 mL) dried (MgSO4) filtered concentrated Purification by flash chromatography on silica gel (EA:H; 1:10)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

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 trifluoromethylsulfonic 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%): 1H NMR (CDCl3, 300 MHz) δ 0.80-0.98 (m, 6 H), 1.40-1.58 (m, 1 H), 1.69-1.87 (m, 2 H), 3.74 (s, 3 H), 3.93-4.06 (m, 1 H), 4.42 (d, 1 H, J=12.0 Hz), 4.68-4.80 (m, 1 H), 7.14-7.32 (m, 5 H) ppm. The organic layer was washed with sat. NaCl (2×10 mL), 1N HCl (2×10 mL), sat. NaCl (2×10 mL) dried (MgSO4) filtered concentrated Purification by flash chromatography on silica gel (EA:H; 1:10)