benzyl N-[(2S)-1-hydroxy-4-methylpentan-2-yl]carbamate

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

Procedure: Subsequently, to a solution of [(1S)-1-(hydroxymethyl)-3-methylbutyl]carbamic acid benzyl ester (4.84 g, 19.3 mmol) in dimethylformamide (145 ml) were added t-butyldiphenylsilyl chloride (6.01 ml, 23.1 mmol) and imidazole (1.57 g, 23.1 mmol) in an ice bath, and then the mixture was stirred at room temperature for 8 hours. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution. The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (19:1→7:1) as the eluant to afford [(1S)-1-(t-butyldiphenylsilyloxymethyl)-3-methylbutyl]carbamic acid benzyl ester (9.22 g, yield 98%) as a colorless oil. the completion of the reaction the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was purified by chromatography on a silica gel column

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

Procedure: Subsequently, to a solution of [(1S)-1-(hydroxymethyl)-3-methylbutyl]carbamic acid benzyl ester (4.84 g, 19.3 mmol) in dimethylformamide (145 ml) were added t-butyldiphenylsilyl chloride (6.01 ml, 23.1 mmol) and imidazole (1.57 g, 23.1 mmol) in an ice bath, and then the mixture was stirred at room temperature for 8 hours. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution. The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (19:1→7:1) as the eluant to afford [(1S)-1-(t-butyldiphenylsilyloxymethyl)-3-methylbutyl]carbamic acid benzyl ester (9.22 g, yield 98%) as a colorless oil. the completion of the reaction the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was purified by chromatography on a silica gel column

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

Procedure: To a solution of L-leucinol (1.00 g, 8.53 mmol) in methylene chloride (30 ml) were added chloroformic acid benzyl ester (1.46 ml, 10.2 mmol) and triethylamine (1.43 ml, 10.2 mmol) in an ice bath, and the mixture was stirred at room temperature for 3 days. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium hydrogencarbonate solution. The obtained organic layer was washed With saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (2:1→1:1) as the eluant to afford [(1S)-1-(hydroxymethyl)-3-methylbutyl]carbamic acid benzyl ester (2.31 g, yield 100%) as a colorless oil. the completion of the reaction the reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium hydrogencarbonate solution The obtained organic layer was washed With saturated aqueous sodium chloride solution dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was purified by chromatography on a silica gel column

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

Procedure: Subsequently, to a solution of [(1S)-1-(hydroxymethyl)-3-methylbutyl]carbamic acid benzyl ester (4.84 g, 19.3 mmol) in dimethylformamide (145 ml) were added t-butyldiphenylsilyl chloride (6.01 ml, 23.1 mmol) and imidazole (1.57 g, 23.1 mmol) in an ice bath, and then the mixture was stirred at room temperature for 8 hours. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution. The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (19:1→7:1) as the eluant to afford [(1S)-1-(t-butyldiphenylsilyloxymethyl)-3-methylbutyl]carbamic acid benzyl ester (9.22 g, yield 98%) as a colorless oil. the completion of the reaction the reaction mixture was partitioned between ethyl acetate and 10% aqueous sodium chloride solution The organic layer was washed successively with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was purified by chromatography on a silica gel column

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

Procedure: To a solution of L-leucinol (1.00 g, 8.53 mmol) in methylene chloride (30 ml) were added chloroformic acid benzyl ester (1.46 ml, 10.2 mmol) and triethylamine (1.43 ml, 10.2 mmol) in an ice bath, and the mixture was stirred at room temperature for 3 days. After checking the completion of the reaction, the reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium hydrogencarbonate solution. The obtained organic layer was washed With saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using n-hexane:ethyl acetate (2:1→1:1) as the eluant to afford [(1S)-1-(hydroxymethyl)-3-methylbutyl]carbamic acid benzyl ester (2.31 g, yield 100%) as a colorless oil. the completion of the reaction the reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium hydrogencarbonate solution The obtained organic layer was washed With saturated aqueous sodium chloride solution dried over anhydrous sodium sulfate filtered concentrated under reduced pressure The residue was purified by chromatography on a silica gel column