Efficient Synthesis of Novel Bridgehead-Substituted Bicyclo[3.2.1]octane-2,4-diones

We report the efficient synthesis of bridgehead-substituted bicyclo[3.2.1]octane-2,4-diones. The key step in their construction is a highly efficient intramolecular [3+2] cycloaddition between a nitrile oxide and an olefin. The reductive ring cleavage of the resulting dihydroisoxazole provides the desired bridgehead-­substituted bicyclo[3.2.1]octane-2,4-diones.