A series ofexo-methylenebenzocycloalkanes with ring sizes 5–8 have been prepared, enriched with13C and also deuterated at the exocyclic position.13C chemical shifts are found to be influenced by the degree of planarity between the aromatic ring and the exocyclic methylene function.13C–13C couplings through one, two, and three bonds have been measured. The1JCCvalues correlate very well with %Scharacter calculations. Values of3JCCare found to be influenced by both dihedral angle and valence angle. The relative propensity for these compounds to isomerize to endocyclic material is discussed. Some earlier spectral assignments for the indene derivative are shown to be in error.