Borane → HCID 10903840, compound

Participants

Reaction Conditions

Reaction Steps

To a 0° C. solution of 2,3-dimethyl-2-butene in THF (43.2 mmol, 1.0 M) is added a solution of borane in THF (43.2 mmol, 1.0 M) dropwise over 20 min. After stirring an additional 60 min at 0° C., tert-butyl (2S,3R)-2-benzyloxycarbonylamino-3-methyl-4-pentenoate (13.15 g, 41.2 mmol) in 20 mL THF is added dropwise, and the resulting solution is allowed to come to 25° C. over 60 min. The solution is cooled again to 0° C. and quenched with 6 ml of 1:1 THF-ethanol, added cautiously, then 40 mL of pH 7.0 phosphate buffer. 40 mL 30% hydrogen peroxide is added and the reaction mixture is stirred at 25° C. for 14 h. The mixture is partially concentrated, added to saturated aqueous sodium chloride, and extracted with ether. The combined organic layers are washed twice with ice-cold saturated aqueous sodium sulfite, water, and saturated aqueous sodium chloride, and dried over magnesium sulfate. Concentration in vacuo and purification by silica gel chromatography (elution with hexanes-EtOAc, 3:2) provides tert-butyl (2S,3R)-2-benzyloxycarbonylamino-3-methyl-5-hydroxypentanoate as an oil (12.3 g, 89%).

Provenance & Evidence