Preparation of Enantioenriched Spirocyclic Scaffolds Transferring Axial Chirality from Borylalkylidenecycloalkanes

Herein, an efficient transference of axial chirality from enantiomerically enriched borylalkylidenecycloalkanes to point chirality is disclosed through the synthesis of spirocyclic valuable compounds via cyclopropanation, borylcyclopropanation, epoxidation, and aziridination. This method shows an interesting stereodivergence process, giving access to different spirocycles with complementary central chirality, emphasizing the lack of enantiomeric erosion along the transference of axial chirality. Eventually, the ring expansion of enantioenriched spirocyclic epoxides gives access to 5‐membered cyclic ketones with high stereoselectivity.