THE PROTON AND C-13 NMR-SPECTRA OF SOME PHENOXATHIIN-DERIVATES

The complete proton and carbon chemical shift assignments have been ma de for 2- and 3-formylphenoxathiin, 2- and 3-formyl-phenoxathiinsulfon e, 2- and 3-acetylphenoxathiin, 2- and 3-methyl-phenoxathiin. In some cases the assignments were made with the aid of II,II-COSY and C,II-CO SY experiments. The analysis suggests that transmission of substituent effects from 3-position (para to sulfur) to the unsubstituted ring ta kes place via a pi-polarization mechanism operating through the sulfur atom. If the substituents are fixed in 2-position (meta to sulfur) th e influence on the unsubstituted ring is small.