The stereochemistry of ledol from Renealmia chrysotrycha: an NMR study.

From the leaves of Renealmia chrysotrycha (Zingiberaceae), we isolated a sesquiterpene alcohol for which spectral data suggested the structure of a 10-aromadendranol. A meticulous NMR investigation, based mainly on vicinal proton-proton coupling constants and NOE interactions, and confirmed by a molecular mechanics calculation, established its relative stereochemistry as that of ledol. This finding resolves several recent literature ambiguities. Three known compounds (aromadendrene, cis-calamenene and palustrol) were also isolated.