A new series of 4-substituted pipecolic acid derivatives was prepared
and incorporated into dipeptoids. The resulting products behave as mod
erately potent CCK-B antagonists but their constrained structure and i
ts comparison with structurally related compounds yield valuable infor
mation about the conformational requirements for optimal recognition o
f the CCK-B receptor by antagonists. (C) 1998 Elsevier Science Ltd. Al
l rights reserved.