The free radical addition reactions of [1.1.1] propellane (1) are described in some detail and allowed the preparation of a wide variety of 1,3-disubstituted bicyclo [1.1.1.] pentanes. The reaction of 1 with free radicals was more rapid than that of bicyclo [1.1.0] butane (2), whereas bicyclo [2.1.0] pentane (3) was relatively inert
The synthesis of the lipophilic chiral amino acid 1 bearing the bicyclo[1.1.1]pentane moiety is described. Linear and cyclic hexapeptides of the type Arg-Arg-Xaa-Yaa-Arg-Phe containing 1 instead of one or two tryptophan residues are prepared by solid phase peptidesynthesis and the antimicrobial and hemolytic activity of the peptides obtained are discussed.