Imidazole → (2RS,3RS)-2-(3,4-dichlorobenzyl)-3-(tert-butyldimethylsilyloxy)butanol

Participants

Reaction Conditions

Reaction Steps

1.14 g of tert-butyl (2RS, 3RS)-2-(3,4-dichlorobenzyl)-3-hydroxybutanoate obtained in Example 123 was dissolved in 10 ml of dimethylformamide, and 0.65 g of tert-butyldimethylchlorosilane and 0.37 g of imidazole were added thereto with stirring under cooling with ice. The mixture was stirred at room temperature for 6 hours. The reaction solution was diluted with ethyl ether, then washed with a saturated sodium hydrogencarbonate aqueous solution and a saturated sodium chloride aqueous solution, and dried over anhydrous magnesium sulfate. The drying agent was separated by filtration, and then the solvent was distilled off under reduced pressure. The residue was dissolved in 10 ml of toluene, and then a 1M toluene solution of diisobutylaluminum hydride was added thereto with stirring under cooling to -78° C. The mixture was stirred at the same temperature for 1 hour. A saturated ammonium chloride aqueous solution was added to the reaction solution with stirring under cooling to -78° C., and the temperature was raised to room temperature. Then, 1N hydrochloric acid and ethyl acetate were added thereto for liquid separation. The organic layer was washed with a saturated sodium chloride aqueous solution and then dried over anhydrous magnesium sulfate. The drying agent was separated by filtration, and then the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography to obtain 0.99 g (yield: 76%) of (2RS, 3RS)-2-(3,4-dichlorobenzyl)-3-(tert-butyldimethylsilyloxy)butanol.

Provenance & Evidence