Based on this energy estimate, it can be considered to belong into class 3 atropisomers (no interconversion, long half-life) . Therefore, the development as an enantiopure compound is selfevident. However, for LY3537982 this is not as clear, while the QM predicted energy barrier was below 25 kcal/mol, suggesting a potential risk for delayed interconversion of the atropisomers (class 2). Interestingly, the putative bioactive atropisomer of LY3537982 appears to exist with lower energy compared to the other enantiomer. This QM estimate with the lower energy of the bioactive enantiomer appears to be somewhat in line what is found in the patent, as the reported ratio of the existing atropisomers with selected derivatives is 45:55, with the latter being the bioactive atropisomer .