Conformational Analysis, Synthesis, and Carbon-13 Spectroscopy of 9,9-Dimethylbicyclononane Derivatives

Article abstract of DOI:10.1021/jo00208a002

A series of 9,9-dimethylbicyclo<3.3.1>nonanes substituted in position 3 and/or 7 has been synthesized.Their conformational properties have been studied by force field calculations and 13C NMR.These studies indicate that, in most of the compounds, the dimethyl bridge substitution force the two cyclohexane rings in the chair conformation.The steric compression imposed on carbons 3 and 7 by this double chair conformation is found to displace their carbon-13 chemical shifts to high field.