Summary The preparation of 2, 2, 5, 5-tetramethyl-3, 6-diketopiperazine (IV) from a- aminoisobutyric acid is described. This diketopiperazine has been converted to 2, 2, 5, 5- tetramethylpiperazine (I) and 2, 2, 5, 5-tetramethyl-3-ketopiperazine (V) by catalytic hydrogenation over copper-chromium oxide as well as by reduction with sodium in butanol.
