Regiochemistry of the ring expansion of unsymmetrically substituted ketones involving β-hydroxyalkylselenides

β-hydroxyalkylselenides derived from unsymmetrically substituted ketones have been rearranged to substituted ketones in the presence of soft electrophiles such as silver tetrafluoraborate or dichlorocarbenes. Although the migration of the more substituted carbon often prevails, subtle variations have been observed depending upon the structure of the starting material and the experimental conditions used.