The enolsilyl ether 2, generated from butynone adduct 3, which is easily av
ailable from the enantiomerically pure cyclopentadiene 1, proved to be a ge
neral building block for polycyclic anellation products to cyclohexenone. A
fter proper adjustment of functional groups in the cycloadducts by means of
high pressure Diels-Alder cycloadditions, the thermal retro-process provid
ed routes to various enantiopure alicyclic and. heterocyclic target compoun
ds in high yields.