Chemistry of the phenoxathiins and isosterically related heterocycles. X. Correlation of the dihedral angles of phenoxathiin analogs with the ¹³NMR chemical shifts of the sulfur bearing la carbon

Abstract

Abstract The observation of a linear relationship between the 13 C‐nmr chemical shifts of the C‐la carbon and the dihedral angle in a series of phenoxathiin analogs is reported. Presently available data, although limited, is presumed to be indicative of a more general behavior which has not been previously recognized or utilized. Extension of this observation to include other sulfur containing tricyclic systems may be expected to provide a useful means for the preliminary estimation of dihedral angles from solution 13 C‐nmr measurements after suitable parameterization.