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 pentacycli c triterpenes taraxerol and myricadiol were isolated. The EtOH extract afforded the [7.0]metacyclophanes, (+/-)-myricanol(4), and myricanone (7). Accurate H-1- and C-13-NMR spectral assignments have been made f or (+/-)-myricanol (4), 5,11,17-tri-O-acetyl-(+/-)-myricanol (5), 11-O -methyl-(+/-)-myricanol (6), and myricanone (7) by a study of the H-1- H-1-COSY, H-1-C-13-COSY (HETCOR), selective INEPT, and 1D NOE experime nts. The structure of (+/-)-myricanol was established by a single crys tal X-ray analysis. Molecular mechanics MM-3(94) calculations have bee n made for (R,Sa)- and (S,Sa)-myricanol, and the bond lengths, bond an gles, and the torsion angles have been calculated for the energy-minim ized conformation.