A mixture of 4-hydroxybutylamine (4.0 g, 44.9 mmol), tert-butyldimethyl-silyl chloride (7.4 g, 49.3 mmol) and imidazole (6.7 g, 98.7 mmol) in dichloromethane (150 mL) was stirred at room temperature for 2 hours. The product mixture was washed successively with aqueous NaHCO3, water, and brine. The organic extract was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. This intermediate silylated aminoalcohol was used without further purification. To a mixture of the amine (1.0 g, 4.9 mmol) and benzyloxyacetaldehyde (0.74 g, 4.9 mmol) in dichloroethane (15 mL) at room temperature, sodium triacetoxyborohydride (1.3 g, 6.3 mmol) was added. The reaction mixture was concentrated under vacuum. The residue was partitioned between ethyl acetate and aqueous sodium carbonate. The organic extract was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluting with 2% methanol in dichloromethane. Collection and concentration of appropriate fractions afforded the title silyloxybutyl-amine.
