To a solution of 3-t-butyldiphenylsilyloxy-1-(4-p-nitrobenzyloxycarbonyl-1,3-thiazol-2-yl)azetidine (93 mg, 0.16 mmol) (obtained as described in Reference Example 2(5)) in anhydrous tetrahydrofuran (4.7 ml) were added acetic acid (0.028 ml, 0.49 mmol) and a solution of 1 M tetrabutylammonium fluoride in tetrahydrofuran (0.48 ml, 0.48 mmol) in an ice bath. The mixture was stirred for 2 hours. After checking the completion of the reaction, the reaction 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 toluene:acetonitrile (2:1) as the eluant to afford 1-(4-p-nitrobenzyloxycarbonyl-1,3-thiazol-2-yl)-3-hydroxyazetidine (42.4 mg, yield 81%) as a pale yellow solid.
