Ab-initio studies of thio-containing monocyclic -lactams: Reactivity and stability

ORGN 574

Milena Shahu, Chemistry Department, American University, 4400 Massachussets Ave. ,N.W, Washington, DC 20016-8014 and Monika Konaklieva, Department of Chemistry, American University, 4400 Massachusetts Avenue,NW, Washington, DC 20016.
The thio-containing monocyclic -lactams, designed as -lactamase inhibitors, were theoretically investigated by quantum chemical methods. The 6-31G** basis set was employed. The molecular geometry and other properties such as frequencies, charges, and LUMO (Lowest Unoccupied Molecular Orbital) energies were analyzed in order to obtain information on the reactivity and stability of these -lactams. The pyramidalization of the lactam nitrogen and the LUMO energy are good indicators of the reactivity of the -lactam rings toward nucleophilic attack. The data obtained from calculations of these novel -lactams are in good agreement with the data provided by structural studies on the current -lactam antibiotics.

Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster

8:00 PM-10:00 PM, Monday, 29 August 2005 Washington DC Convention Center -- Hall A, Sci-Mix

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005