Abstract Various new C 2-symmetric bidentate ligands, bearing phosphorus, nitrogen, and sulfur, were obtained in an efficient manner, starting from (±)-trans-3- methylidenecyclopropane-1, 2-dicarboxylic acid (Feist's acid;(±)-trans-3). The structures of the new bidentate ligands, di (tert-butyl)(±)-[(trans-3-methylidenecyclopropane-1, 2-diyl) dimethanediyl] biscarbamate ((±)-9),(±)-(trans-3-methyldienecyclopropane-1, 2-diyl) ...