Extensive 1D, 2D NMR Spectra of Some [7.0]Metacyclophanes and X-ray Analysis of (±)-Myricanol

From the hexane extract of the bark of Myrica cerifera, the pentacyclic triterpenes taraxerol and myricadiol were isolated. The EtOH extract afforded the [7.0]metacyclophanes, (±)-myricanol ( 4 ), and myricanone ( 7 ). Accurate 1 H- and 13 C-NMR spectral assignments have been made for (±)-myricanol ( 4 ), 5,11,17-tri- O -acetyl-(±)-myricanol ( 5 ), 11- O -methyl-(±)-myricanol ( 6 ), and myricanone ( 7 ) by a study of the 1 H− 1 H-COSY, 1 H− 13 C-COSY (HETCOR), selective INEPT, and 1D NOE experiments. The structure of (±)-myricanol was established by a single crystal X-ray analysis. Molecular mechanics MM-3(94) calculations have been made for ( R,Sa)- and ( S, Sa )-myricanol, and the bond lengths, bond angles, and the torsion angles have been calculated for the energy-minimized conformation.