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

A mild method for synthesizing α-methyl ketones from substituted cyclopropanols is reported. This process, catalyzed by [Cp∗IrCl2]2, cleaves cyclopropanol rings regioselectively and more efficiently than the other conditions examined. While tertiary cyclopropanols afford α-methyl ketones, secondary cyclopropanols and cyclopropyl silyl ethers are less reactive and yield other isomerization products.