The complete series of enantiopure 2, 6-methylated piperazines was synthesized utilizing two alternative reactions in the key bond-forming step. The dimethyl enantiomers,(2R, 6R)- and (2S, 6S)-2, 6-dimethylpiperazine (1, 2), were prepared using either a diastereoselective triflate alkylation or a novel intramolecular Mitsunobu reaction to set the required stereochemistry. The monomethyl derivatives,(R)-and (5')-tert-butyl 2-methyl-1- ...