The aliphatic Claisen rearrangement is a well-established protocol for the synthesis of γ,δ-unsaturated carbonyl compounds such as esters (Johnson-Claisen) , carboxylic acids (via enolsilanes, Ireland-Claisen) or amides (Eschenmoser-Claisen) . In contrast, the corresponding γ,δ-unsaturated ketones are less commonly accessed via the Claisen rearrangement. While the Johnson-Claisen variant readily proceeds under mild carboxylic acid catalysis with ortho esters, typical literature conditions for promoting the corresponding ketone/ketal Claisen rearrangement include stronger acids, such as H3PO4 and the use of autoclaves or high pressures (Scheme 1). For a limited range of allylic alcohols, Daub and co-workers reported success with mild carboxylic acid catalysts. 7e-f Alternatively, the aliphatic Claisen rearrangement reactions to give ketones can be promoted by Hg 2+ salts under milder conditions, but the toxicity of Hg 2+ is an obvious deterrent. 9