In this paper we report a general synthesis of novel partially saturated, heterobicyclic arginine side chain mimetics III containing a five- or six-membered N-heterocyclic ring optionally substituted by amino or guanidino groups ( Fig. 1). The cyclohexane ring, which mimics the arginine methylene side chain, introduces conformational rigidity into the molecule. These compounds are interesting mimetics of the arginine side chain, which can be easily functionalised via the ...