Regioselectivity in the Acid Cleavage of Bicyclo[4.1.0]Heptan-3-Ones

Abstract Acid-promoted cyclopropane cleavage reactions have been employed with great success for the generation of angular methyl groups.2 Sims has shown that the regioselectivity of such reactions may be influenced by acid strength.2d We now report a case in which steric factors appear to direct the cleavage pathway.