Photocycloaddition of α,β-unsaturated-γ-lactam with ethylene. Synthesis of conformationally restricted glutamate analogs, L-2-(2-carboxycyclobutyl)glycines

Article abstract of DOI:10.1016/S0040-4039(97)10807-3

Both (2S,1'S,2'S)- and (2S, 1'S,2'R)-isomers of 2-(2-carboxycyclobutyl)glycine (CBG-I, 1b) and (CBG-III, 2b) are synthesized in a stereoselective manner via a [2+2] photocycloaddition of α,β-unsaturated-γ-lactam 3 with ethylene in acetone. The extended type of isomer 1b showed a weak activity on group II metabotropic glutamate receptors (mGluR2) of rat brain.