Abstract The intramolecular cyclopropanation of β, γ-unsaturated metalated epoxides derived from 11 yielded the highly strained tricyclic intermediates 7. The facile hydrolysis of the latter species afforded the α-keto spirocyclopropanes 8 in a stereospecific fashion. Indeed, the stereochemistry of the starting alkenes 11d− e governs the relative configuration of the cyclopropanes 8d− e. Furthermore, these spiro systems readily underwent acid- ...