Catalytic Hydrogenation Using Nickel Boride The catalyt,ic hydrogenation of endo-norhomene-eis-5,6diczrhoxylicacid in the presence of a platinum catalyst by Fieser's' adaptation of Brown's technique2 is an excellent experiment for demonstrating this type of reaction in the undergraduate organic laboratory. To add variation and economy to the experiment, our students have recently used Fieser's"balloon technique" with nick1 boridea as a catalyst rather than platinom. The catalyst and hydrogen in this case vere generated by treatment of an aqueous solution of the norbornene compound and nickel chloride with excess sodium borohydride. Yields of the recrystallized norbornane product were typically about 70% and were shown by nmr analysis t o be free of the unsaturated acid. The experimental procedure is essentially as given by Fieser' with several modifications and can he ohtainedfram the author.
'FIKSER, LOUISF.,"Organic Experiments,'' (4thed.l I). C. Heath and Co., Boston 1964, p. 86. BROWN, H.C., AND BROWN,C. A,, J . Amer. Chem. Soc., 84,1493(1962). 'BROWN,H. C.,AND BROWN,C. A,, J . Amer. Chem. Soc, 85,1003(1963). l
JAMES W. PAVLIK UNIVERSITYO F WISCONSIN-RIVERFALLS RIVERFALLS, WISCONSIN 54022
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Journal of Chemical Education