benzyl N-[(2S)-1-amino-3,3-dimethyl-1-oxobutan-2-yl]carbamate

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

Procedure: To a solution of benzyl [(1S)-1-(aminocarbonyl)-2,2-dimethylpropyl]carbamate (Step 1, 3.7 g, 14 mmol) in THF (40 mL) was added 10% Pd/C (710 mg). The flask was evacuated and flushed with H2 gas and this process was repeated three times. The flask was filled with H2 gas (4 atm) and stirred for 3 h at rt. Then the reaction mixture was filtered through a pad of Celite and concentrated in vacuo to give the title compound as white solid (crude; 1.8 g) The flask was evacuated flushed with H2 gas The flask was filled with H2 gas (4 atm) Then the reaction mixture was filtered through a pad of Celite concentrated in vacuo

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

Procedure: To a solution of benzyl [(1S)-1-(aminocarbonyl)-2,2-dimethylpropyl]carbamate (Step 1, 3.7 g, 14 mmol) in THF (40 mL) was added 10% Pd/C (710 mg). The flask was evacuated and flushed with H2 gas and this process was repeated three times. The flask was filled with H2 gas (4 atm) and stirred for 3 h at rt. Then the reaction mixture was filtered through a pad of Celite and concentrated in vacuo to give the title compound as white solid (crude; 1.8 g) The flask was evacuated flushed with H2 gas The flask was filled with H2 gas (4 atm) Then the reaction mixture was filtered through a pad of Celite concentrated in vacuo

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

Procedure: To a solution of N-[(benzyloxy)carbonyl]-tert-leucine (prepared according to the procedure in the literature; Emily, M. S. et al. Tetrahedron 2001, 57, 5303-5320.; 3.7 g, 14 mmol) in DMF (80 mL) were added ammonium chloride (900 mg, 17 mmol), triethylamine (5.9 mL, 42 mmol), HOBt (2.8 g, 18 mmol) and EDAPC (3.1 g, 18 mmol) and stirred at rt. After 17 h, the reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate (100 mL) and extracted with ethyl acetate (100 mL×3). The combined organic layers were washed with water (100 mL×3), brine (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (2/1-1/1) to afford 3.0 g (82%) of the title compound. the reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate (100 mL) extracted with ethyl acetate (100 mL×3) The combined organic layers were washed with water (100 mL×3), brine (50 mL) dried over sodium sulfate filtered concentrated in vacuo The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (2/1-1/1)

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

Procedure: To a solution of benzyl [(1S)-1-(aminocarbonyl)-2,2-dimethylpropyl]carbamate (Step 1, 3.7 g, 14 mmol) in THF (40 mL) was added 10% Pd/C (710 mg). The flask was evacuated and flushed with H2 gas and this process was repeated three times. The flask was filled with H2 gas (4 atm) and stirred for 3 h at rt. Then the reaction mixture was filtered through a pad of Celite and concentrated in vacuo to give the title compound as white solid (crude; 1.8 g) The flask was evacuated flushed with H2 gas The flask was filled with H2 gas (4 atm) Then the reaction mixture was filtered through a pad of Celite concentrated in vacuo

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

Procedure: To a solution of N-[(benzyloxy)carbonyl]-tert-leucine (prepared according to the procedure in the literature; Emily, M. S. et al. Tetrahedron 2001, 57, 5303-5320.; 3.7 g, 14 mmol) in DMF (80 mL) were added ammonium chloride (900 mg, 17 mmol), triethylamine (5.9 mL, 42 mmol), HOBt (2.8 g, 18 mmol) and EDAPC (3.1 g, 18 mmol) and stirred at rt. After 17 h, the reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate (100 mL) and extracted with ethyl acetate (100 mL×3). The combined organic layers were washed with water (100 mL×3), brine (50 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (2/1-1/1) to afford 3.0 g (82%) of the title compound. the reaction mixture was quenched by addition of saturated aqueous sodium bicarbonate (100 mL) extracted with ethyl acetate (100 mL×3) The combined organic layers were washed with water (100 mL×3), brine (50 mL) dried over sodium sulfate filtered concentrated in vacuo The residue was purified by column chromatography on silica gel eluting with hexane/ethyl acetate (2/1-1/1)