The a-oxygenation of carbonyl compounds is an important method for C-O bond formation and it has been broadly studied before. In principle, vinylogous extension of the a-oxygenation reaction to ?-enolizable-a,�-unsaturated carbonyl compounds can be used to prepare ?-hydroxy-a,�-unsaturated carbonyl compounds, which are common in natural products. The main purpose of this research was to develop a catalytic enantioselective reaction. For this purpose, we prepared the silyl dienol ether of 6,6-dimethylcyclohexen-2-enone. It was treated with nitrobenzene in the presence of three different ligands.  The reaction indeed gave the ?-hydroxy ketone as the only product, but no enantioselectivity was observed. We also extended the reaction to ?-amination by treating the silyl dienol ether with DEAD and the same three ligands. The chiral phosphoric acid did lead to the formation of the desired ?-amination product with similar yield to those obtained with nitrobenzene, but without observable enantioselectivity.

γ-Oxygenation and amination of α,β-unsaturated cyclic ketones by vinylogous
Mukaiyama adol reaction

241st National Meeting (2011)

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γ-Oxygenation and amination of α,β-unsaturated cyclic ketones by vinylogous Mukaiyama adol reaction