ピペラジン類の合成研究 (第8報)

α (trans)-及びβ (cis)-2,3-Dimethylpiperazines の合成

抄録

It was found that the hydrogenation of 2, 3-dimethyl-5, 6-dihydropyrazine to form 2, 3-dimethylpiperazine resulted in the selective formation of only one of cis- or trans- isomers according to the kind of the reduction agent used. Reduction with sodium and ethanol only afforded the trans compound, while that with lithium aluminum hydride gave the cis compound alone. Catalytic reduction with Raney nickel, platinum oxide, or palladium-carbon chiefly afforded the cis compound, with a minute amount of the trans compound. Both cis and trans compounds, and their derivatives agree with Auwers-Skita's law.