Different approaches to conformational analysis: A comparison of completeness,efficiency, and reliability based on the study of a nine-membered lactam

Different methods such as molecular dynamics, systematic, or stochastic search and a special “generic shape” algorithm have been employed in the conformational analysis of a nine-membered lactam. Furthermore, crystal data were used to generate conformations of the compound under consideration. The various methods are compared in terms of their efficiency and completeness in the search for conformations with an energy content of up to 60 kJ/mol above the global minimum. Additionally, the generated conformations have been optimized by different techniques, molecular mechanics and quantum chemical calculations, to compare the number of existing local minima and their relative energies and geometries.