Substituent effects on13C and1H chemical shifts in 3-benzylidene-2,4-pentanediones
摘要:
AbstractSubstituent effects on the 13C and 1H chemical shifts have been studied for derivatives of 3‐benzylidene‐2, 4‐pentanedione. A significant correlation has been found between chemical shifts of the Z carbonyl group (C‐2) and Hammett constants, while no correlation has been found for the E carbonyl group (C‐4). Attempts have been made to determine the structural factors which influence these effects. The conformation of 3‐benzylidene‐2, 4‐pentanediones has been determined by 13C and 1H NMR spectroscopy.