dirhodium tetraacetate in dichloromethane

1: 81 percent / n-BuLi, diisopropylamine / tetrahydrofuran / -78 °C 2: 91 percent / methanesulfonyl azide, triethylamine / acetonitrile / 3 h / Ambient temperature 3: 42 percent / Rh2(OAc)4 / CH2Cl2 View Scheme

1: 91 percent / methanesulfonyl azide, triethylamine / acetonitrile / 3 h / Ambient temperature 2: 42 percent / Rh2(OAc)4 / CH2Cl2 View Scheme

1: 85 percent / diisopropyl amine, n-BuLi / tetrahydrofuran / 1.) -78 deg C, 2.) r.t. 2: 81 percent / n-BuLi, diisopropylamine / tetrahydrofuran / -78 °C 3: 91 percent / methanesulfonyl azide, triethylamine / acetonitrile / 3 h / Ambient temperature 4: 42 percent / Rh2(OAc)4 / CH2Cl2 View Scheme