Pyrazine chemistry. III. Synthesis and stereochemistry of 1,4-Dimethyl and 1,4-Diacetyl derivatives of 3,6-Dibenzylpiperazine-2,5-dione

Abstract

The trans- and (±) cis-isomers of 1,4-dimethyl-and 1,4-diacetyl-3,6-dibenzylpiperazine-2,5-dione were synthesized. The hydriodic acid reduction of 3,6-dibenzylidene-1,4-dimethylpiperazine-2,5-dione gave (±)-cis-3,6-dibenzyl-1,4-dimethylpiperazine-2,5-dione although this product has previously been assigned the trans-geometry. The unknown isolated from the permanganate oxidation of (±)-cis- 1,4-diacetyl-3,6-dibenzylpiperazine-2,5- has been identified as the corresponding trans-isomer.