Tetrabutylammonium Fluoride → 1-[4-(Benzenesulfonylamino)methyl-1,3-thiazol-2-yl]-3-hydroxyazetidine

To a solution of 3-t-butyldiphenylsilyloxy-1-[4-(benzenesulfonylamino)methyl-1,3-thiazol-2-yl]azetidine (2.79 g, 4.95 mmol) (obtained as described in Reference Example 65(1)) in anhydrous tetrahydrofuran (140 ml) was added a solution of 1.0 M tetra-n-butylammonium fluoride in tetrahydrofuran (5.94 ml, 5.94 mmol) in an ice bath and the mixture was stirred in an ice bath for 2 hours. After checking the completion of the reaction, the mixture was partitioned between ethyl acetate and saturated aqueous sodium hydrogencarbonate solution. The organic layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using ethyl acetate as the eluant to afford 1-[4-(benzenesulfonylamino)methyl-1,3-thiazol-2-yl]-3-hydroxyazetidine (1.06 g, yield 66%) as a white solid.