First intramolecular geminal acylation: synthesis of bridged bicyclic diketones

Bicyclic diketones have been produced by Lewis acid-promoted geminal acylations involving cyclic acyloins tethered to an acetal. This intramolecular process must proceed via a mode of reaction which, due to steric hindrance, is not seen in the intermolecular version of the geminal acylation.