Carbon-13 NMR spectra of heterocycles. Sultones and sultams.

The ¹³C NMR spectra of 1,3-propanesultam, 2,4-butanesultam, 1,4-butanesultam, 1,3-propanesultone and 1,4-butanesultone, as well as some of their unsaturated analogs 2,4-dimethylbuta-1,3-diene-1,4-sultone and 2,4-dimethylbuta-1,3-diene-1,4-sultam, have been recorded. The observed chemical shift data for the sultams and sultones can be explained mainly on the basis of inductive effects. The δ values of the dienesultone and the dienesultam are mainly affected by M-effects. ¹H NMR as well as mass spectra have.