| abstract |
Compounds of the formula:wherein R<sup>1</sup> stands for an alk-2-enyl radical of not more than 5 carbon atoms or a furylmethyl radical, R<sup>2</sup> stands for an alk-2-enyl or alkyl radical of not more than 5 carbon atoms or a furylmethyl radical, >N-A, B, D, E and F stand for defined amino acid or aza-amino-acid residues, and in particular one or both of B and D stand(s) for an amino acid residue of the formula -NH.C(1-3C alkyl)(1-3C alkyl).CO- or a similar residue, and X stands for -OR<sup>7</sup> or -NR<sup>7</sup>R<sup>8</sup>, wherein R<sup>7</sup> and R<sup>8</sup>, which may be the same or different, stand for hydrogen or a (1-4C)alkyl radical, and wherein the linkages are all conventional peptide linkages or in the case of D-E the peptide linkage is replaced by the group -CH<sub>2</sub>S-, and pharmaceutically-acceptable salts thereof. Processes for the manufacture of the compounds. Pharmaceutical compositions comprising one of the compounds and a pharmaceutically-acceptable diluent or carrier. The compounds are selective opiate δ-receptor antagonists. |