Benzo[c]quinolizin-3-ones: A Novel Class of Potent and Selective Nonsteroidal Inhibitors of Human Steroid 5α-Reductase 1

The study focused on the stereochemical assignments of benzo[c]quinolizin-3-ones, a novel class of nonsteroidal inhibitors of human steroid 5α-reductase 1. The researchers used semi-empirical AMI studies and ¹H NMR spectroscopy to determine the relative stereochemistry of these compounds. They found that the nitrogen atom in these compounds exhibited an intermediate hybridization between sp² and sp³, influencing the chair-like conformation of the A ring. The stereochemistry of various methyl-substituted derivatives was assigned based on coupling constant values and chemical shifts observed in the NMR spectra. The findings provided insights into the structural characteristics necessary for the inhibitory activity of these compounds.