The General Procedure for Dissolving Zinc Metal Reduction

The General Procedure for Dissolving Zinc Metal Reduction 

A three-necked flask, fitted with a reflux condenser and septa, was purged with Ar for 15 min. The Rieke zinc/THF slurry (purchased from Rieke Metals, LLC, 

1001 Kingbird Road, Lincoln, NE 68521) was transferred to the flask via syringe. After the Zn suspension was heated to reflux, a methanol solution of the organic compound to be reduced was added, followed by addition of water. 

The ratio of THE methanol water used was 7 5 1. A representative reduction to 8.0 ml of a stirred suspension of 5% Rieke zinc, 6.12 x 10 mol, a solution of 4.08 X 10 mol of phenylacetylene dissolved in 5.60 ml of methanol was slowly added, followed by dropwise addition of 1.10 ml of water. After refluxing for 2.5 h under argon, the solution was cooled and 150 ml of ether were added. 

The resulting mixture was filtered through Celite and extracted successively with 10% ammonium chloride (25 ml), 10% sodium bicarbonate (25 ml), and saturated sodium chloride (25 ml). After drying over anhydrous magnesium sulfate, the solvents were stripped by rotary evaporation. The yield and composition of the resulting crude product were determined by proton NMR. 

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