BaMnO4 in dichloromethane 37 h; Ambient temperature;

1: N'-cyclopentylidene-N,N-dimethylhydrazine With n-butyllithium 2: 5-iodo-penta-1,2-diene 3: With silica gel in dichloromethane

1.1: LDA / tetrahydrofuran / 2 h / -78 - 20 °C 1.2: tetrahydrofuran / -78 - 20 °C 2.1: 1.53 g / Amberlyst / acetone / 4 h / 20 °C View Scheme

1: 39.1 percent / cuprous bromide, diisopropylamine / dioxane / 21 h / Heating 2: 57 percent / barium manganate / CH2Cl2 / 37 h / Ambient temperature View Scheme

1: 83 percent / L-Selectride / tetrahydrofuran / -78 deg C, 2 h, to room temp., 4 h 2: 39.1 percent / cuprous bromide, diisopropylamine / dioxane / 21 h / Heating 3: 57 percent / barium manganate / CH2Cl2 / 37 h / Ambient temperature View Scheme

1: 58.1 percent / p-toluenesulphonylhydrazide / acetic acid; CH2Cl2 / -17 deg C, 1 h; -1 to -2 deg C overnight and room temp., 2 h 2: 83 percent / L-Selectride / tetrahydrofuran / -78 deg C, 2 h, to room temp., 4 h 3: 39.1 percent / cuprous bromide, diisopropylamine / dioxane / 21 h / Heating 4: 57 percent / barium manganate / CH2Cl2 / 37 h / Ambient temperature View Scheme