Sulfhydantoin from glycine or L-valine is used as a precursor via heterocyclic opening reactions. The operating conditions used during electrophilicity tests influence the reactivity of heterocycles, the best control of the electrophilicity of our molecules, and consider as well as their use as enzyme inhibitors. The regioselectivity of the reactions carried out in various nucleophilic media leads to three new linear products derived from acetamide and butanamide and which are analogous to the peptide structures. The structures of the synthesized products 3-5 have been elucidated and confirmed by the usual spectroscopic methods. A theoretical study based on the DFT/PW6B95 method combined with the basic set 6-311G (2d,p) was carried out to determine the structural and electronic parameters such as the energy parameters, the molecular electrostatic potential (MEP), the natural bonding of orbitals (NBO), non-covalent interactions (NCI) and 1 H NMR. Sulfhydantoin from glycine or L-valine is used as a precursor via heterocyclic opening reactions. The operating conditions used during electrophilicity tests influence the reactivity of heterocycles, the best control of the electrophilicity of our molecules, and consider as well as their use as enzyme inhibitors. The regioselectivity of the reactions carried out in various nucleophilic media leads to three new linear products derived from acetamide and butanamide and which are analogous to the peptide structures. The structures of the synthesized products 3-5 have been elucidated and confirmed by the usual spectroscopic methods. A theoretical study based on the DFT/PW6B95 method combined with the basic set 6-311G (2d,p) was carried out to determine the structural and electronic parameters such as the energy parameters, the molecular electrostatic potential (MEP), the natural bonding of orbitals (NBO), non-covalent interactions (NCI) and 1 H NMR.