Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... The conversion of 6,6-dimethylbicyclo[3.1.1]heptan-3-one into 3,6,6-trimethylbicyclo[3.1.1]-heptene -2(“orthodene”), formerly considered to be a naturally occurring isomer of α-pinene, is described. ... Incidentally, structure 15 has been postulated for “orthodene” by YR Naves, ...