Synthesis of a-methyl ketones by a selective, iridium-catalyzed cyclopropanol ring-opening reaction

A mild method for synthesizing a-methyl ketones from substituted cyclopropanols is reported. This process, catalyzed by [Cp*IrCl sub(2)] sub(2), cleaves cyclopropanol rings regioselectively and more efficiently than the other conditions examined. While tertiary cyclopropanols afford a-methyl ketones, secondary cyclopropanols and cyclopropyl silyl ethers are less reactive and yield other isomerization products.