Synthesis of 6,6-dicarboxy-3,4-methano-L-proline, a new constrained glutamate analog endowed with neuroprotective properties

6,6-Dicarboxy-3,4-methano-L-proline (L-DCMP, 7) has been prepared by the rhodium(II)acetate dimer catalyzed decomposition of dimethyl diazomalonate in the presence of a 3,4-didehydroproline derivative. When evaluated against NMDA- and kainate-induced toxicity in cultured cortical neurons, L-DCMP (7) exhibited good neuroprotective activity.