Abstract Preparatively useful reaction conditions for the anionic oxy-Claisen rearrangement of an α-allyloxy ketone (6) possessing acidic α-and α′-hydrogens are described. The reaction rate and efficiency are strongly influenced by both solvent and counterion. The product, 8, although formally the product of [3, 3]-sigmatropic rearrangement of enolate 7, may in fact arise via a [2, 3]-Wittig followed by one or more [1, 2]-acyloin rearrangements.
