CONFORMATIONAL-ANALYSIS OF ANALOGS OF FENTANYL - A THEORETICAL APPROACH - POSSIBLE INFLUENCE OF THE ANOMERIC EFFECT ON ITS BIOLOGICAL-ACTIVITY

MM2 and AM1 calculations have been carried out on eight different form s of fentanyl in order to identify structural features which correlate with the anesthesic activity of this compound. Eight molecules were e xamined each arising from different substitutions of C-3 and C-5 of th e piperidine ring with N, O, or S atoms. The chair conformation with a n axial anilide group was found to have the lowest energy among the st ructures analyzed. Our results suggest that two of the analogs could b e potentially as effective as fentanyl.