Improved synthesis and in vitro/in vivo activities of natural product-inspired, artificial glutamate analogs Original Research Article

Here, we report our second-generation synthesis of 12 artificial glutamate analogs, starting from heterotricycle intermediates 3a–3d, readily prepared in three steps including tandem Ugi/Diels-Alder reactions. The new synthesis employs imidate intermediates for the deoxygenation of pyrrolidones (10a–10d to 6a–6d), and each advanced intermediate 6a–6d was diversified into three glutamate analogs (1a–1d, 5a–5d, 7a–7d) in 1–2 steps.