A tricyclic diterpene ketone, valparolone, with a new carbon skeleton was isolated from the aerial parts of Halimiumviscosum. Its structure was established by chemical transformation of valparene and its absolute stereochemistry was stablished by CD. Therefore the absolute configuration of valparene was confirmed.
Nine new valparane diterpenoids have been isolated from Halimiumviscosum, Valparaíso. Their structures were determined by spectroscopic methods and/or chemical correlations.