Functionalized α,α-dibromo esters through Claisen rearrangements of dibromoketene acetals.

Allylic alcohols can be transformed into γ,δ-unsaturated α,α-dibromo esters through a two-step process: formation of a bromal-derived mixed acetal, followed by tandem dehydrobromination/Claisen rearrangement. The scope and selectivity of both steps have been investigated. The product α,α-dibromo esters were subjected to various carbon-carbon bond-forming reactions, oxidations, and lactonizations.