Novel group II metabotropic glutamate receptor (mGluR) antagonists, 3-alkoxy-2-amino-6- fluorobicyclo [3.1. 0] hexane-2, 6-dicarboxylic acid derivatives 11 and 12, were discovered by the incorporation of a hydroxy or alkoxyl group onto the C-3 portion of selective and potent group II mGluR agonist 5,(1 R, 2 S, 5 R, 6 R)-2-amino-6-fluorobicyclo [3.1. 0] hexane- 2, 6-dicarboxylic acid. Among these compounds,(1 R, 2 R, 3 R, 5 R, 6 R)-2-amino-3-(3, 4- ...