Oxygen‐17 NMR study of electronic and steric effects in furan‐2,3‐dione derivatives

17 O NMR was used to probe the steric and electronic substituent effects in furan-2,3-dione derivatives. The carbonyl 17 O chemical shifts correlate with Hammett constants and IR carbonyl stretching band frequencies for 5-(parasubstituted-phenyl)furan-2,3-diones