13C Nuclear Magnetic Resonance Studies. 47. 13C Spectra of some exo-Methylenecycloalkanes and -norbornanes

The shielding effects of the exo-methylene group on neighboring carbons in several cycloalkanes, methylcyclohexanes, and in the norbornane ring system have been characterized by 13C n. m. r. examination of 28 compounds. The results are compared with those for the carbonyl group and the utility of these data for structural elucidations is discussed. The more distinctive trends exhibited by the methyl carbons in these systems are compared with those for cyclohexanes, cyclohexanones, norbornanes, and norcamphors.