In a flame-dried three-neck flask, a solution of 2-(benzyloxymethyl)-2H-tetrazole (2.01 g, 10.57 mmol) and tetramethylethylenediamine (3.16 mL, 21.4 mmol) in diethyl ether (30 mL) was cooled to −78° C. and treated with the dropwise addition of n-butyllithium (1.6 M in hexanes, 7.3 mL, 11.62 mmol), causing the color of the solution to turn dark red. The mixture was stirred for 10 minutes, then transferred via canulus to a solution of tributyltin chloride (2.9 mL, 10.57 mmol) in diethyl ether (20 mL) which had been pre-cooled to −78° C. The reaction was stirred for 45 minutes, then quenched with saturated ammonium chloride solution. The mixture was allowed to come to room temperature, and the layers were separated. The aqueous phase was extracted 3× with ethyl acetate, and the combined organic phases were washed with brine, dried over sodium sulfate, and concentrated in-vacuo. The residue was purified over silica gel, eluting with 1% then 5% then 10% ethyl acetate/hexanes to yield the title compound (3.0 g, 60% yield) as a colorless oil.
