1.1: zinc; methanesulfonic acid / tetrahydrofuran / |Inert atmosphere; |Reflux 1.2: 50 - 60 °C 2.1: diethyl methoxy borane / tetrahydrofuran / 1 h / -70 - -60 °C / |Inert atmosphere 2.2: 3 h / -70 - 60 °C / |Inert atmosphere 3.1: methanesulfonic acid / acetone / 3 h / 20 °C 4.1: hexaammonium heptamolybdate tetrahydrate; dihydrogen peroxide / ethanol; water / 20 - 50 °C View Scheme