In the present study, the synthesis of the 5.5. 6. and 5.6. 5. spiro bicyclic lactam PLG peptidomimetics, compounds 3 and 4, respectively, was undertaken. These peptidomimetics were designed to examine the following:(1) the effect that changing the size of the thiazolidine and lactam ring systems would have on the ability of these systems to mimic the type-II β-turn and (2) the effect that these structural perturbations would have on the ability ...