Synthesis and stereochemistry of 1,4-diazabicyclo[4,3,0]nonane-2,5,9-triones

Abstract

1,4-Diazabicyclo[4,3,0]nonane-2,5,9-triones have been prepared by two synthetic routes. The first (Scheme 1) involves cyclisation of α-aminoacyl glutamic acids to 3,6-dioxo-2-piperazinepropionic acids, which undergo a second cyclisation on refluxing with an acid anhydride. In the second (Scheme 2) the bicyclic system is obtained by direct cyclisation of α-acetamidoacyl glutamic acids. N.m.r. studies and optical rotations have been used in the elucidation of the stereochemistry of the products.