Abstract The three-dimensional structure of tricyclic compounds with a zero-bridge to one bridgehead atom is determined by the underlying spirocyclic framework.(–)-Khusimone (1), the principal odorant of vetiver oil (content up to 2%), is such a tricyclic norsesquiterpene, and dissection of the 7, 8-bond between the methylene and the gem-dimethyl unit of 1 results in a spirocycle extending over an almost identical molecular volume and shape. ...
