Unusual 1,2-migration in organoaluminiun chemistry, promoted by BF3.OEt2

Article abstract of DOI:10.1016/S0040-4039(00)88783-3

Lithim dihydropyranyl or dihydrofuranyl triorganoaluminates react with cyclohexene oxide or benzaldehyde in the presence of BF₃. OEt₂, not by nucleophilic attack product 1, but by 1,2 migration of α substituent from Al to the ?-carbon, with concomitant reaction with the electrophile on the β-carbon, giving rise to product 2.