Conformational study of fentanyl and its analogs.2. Conformational space and electronic properties of ohmefentanyl

Abstract

The conformational space and electronic properties of the two physiologically active stereoisomers of ohmefentanyl have been studied by molecular mechanics and semiempirical molecular orbital (PM3) calculational methods. The global minimum conformations of the two stereoisomers were found, as were other conformations present in the low energy region up to 10.5 kJ/mol above the global minima. The electronic properties of the two isomers, in their receptor-recognized conformations, are very similar and the important difference in their activities may be attributed primarly to their conformatonal characteristics.