Synthesis of Nonenolizing 2-Acylcyclohex-2-enones

Cyclohexanones 2b and 2c represent the first examples of nonenolizing 2-acylcyclohex-2-enones, as they bear H-atoms neither at C(4) or C(6) of the enone ring, nor at the C-atom vicinal to the exocyclic carbonyl group. While the CF3CO group in 2b (and the Ac group in 2a) are coplanar to the enone double bonds, the pivaloyl group in 2c, for steric reasons, is out of plane. Compounds 2 exhibit a pronounced sluggishness in both thermal and light-induced bimolecular reactions.