Determining the absolute configuration of benzopyrenomycin by optical rotation, electronic circular dichroism, and population analysis of different conformations via DFT methods and experiments

In this work, we have studied the absolute configuration of benzopyrenomycin using different density functional theory (DFT) methods, such as optical rotation (OR), electronic circular dichroism (ECD), and conformation distribution analysis for three kinds of Mosher esters at different levels, e.g., B3LYP/6-31G(d), B3LYP/6-311+G(d), and B3LYP/6-311++G(2d,p) in the gas phase and in solution, respectively. Careful investigations for different chiral Mosher esters using DFT theory exhibited the application conditions for certain chiral molecules in absolute configuration determination. Benzopyrenomycin possesses a unique benzo[a]pyrene-type skeleton and shows strong cytotoxicity against various tumor-cell lines.