A novel amino alcohol-based Ir bifunctional complex acts as an efficient catalyst for oxidative lactonization of 1, 4-or 1, 5-diols with a substrate-to-catalyst molar ratio of 200-1000 in acetone or butanone. The reaction proceeds with broad functional group tolerance to give lactone in high yield at room temperature. The catalyst precursor Cp* IrCl [OCH2C (C6H5) 2NH2] is isolated and characterized by a single-crystal X-ray analysis.