Synthesis of 6,8-diazabicyclo

[formula: see text] Starting with the proteinogenic amino acid (S)-glutamate, a general method for the synthesis of 3-(piperazin-2-yl)propionic acid esters 7 with various substituents at N-4 of the piperazine ring system is presented. An intramolecular ester condensation of 7 is the key step in the formation of the 6,8-diazabicyclo[3.2.2]nonane derivatives 8-10, which are of interest as conformationally restricted piperazines.