The first series of conformationally constrained analogues of homotaurine is reported. The partial constriction of the skeleton Was realized through the insertion of a cyclopropyl ring, between the alpha,beta- and beta,gamma-positions, thus affording, respectively, trans- and cis-2-aminomethylcyclopropane-1-sulfonic acids and trans- and cis-(2-aminocyclopropyl)methanesulfonic acids. The resolution of all four racemic mixtures was accomplished using HPLC system carrying the polysaccharide-based Chiralpak (R) IB (R) column as the chiral stationary phase. The Coupling with an 'Evaporative Light Scattering Detector (ELSD)' has been particularly valuable during the chromatographic study. (C) 2009 Published by Elsevier Ltd.