To a mixture of 3-chloro-2-hydroxypropyl 4-methylbenzenesulfonate (17.4 g) and imidazole (13.4 g) in DMF (130 mL) was added tert-butyl(chloro)dimethylsilane (14.9 g), and the mixture was stirred for 64 hr. Saturated aqueous sodium hydrogen carbonate solution was added to the reaction mixture, and the mixture was extracted with hexane. The extract was dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (20.3 g).
