in tetrahydrofuran; water 528 h; Ambient temperaturepH=1.1; Title compound not separated from byproducts;

in tetrahydrofuran; water 48 h; HeatingpH=7;

in tetrahydrofuran; water 48 h; HeatingpH=7;

1,4-diazabicyclolt;4.3.0gt;non-5-ene in diethyl ether 3 h; Ambient temperature;

1: 96 percent / Br2 / CH2Cl2; CHCl3 / 0.67 h / -70 °C 2: 42 percent / 1,4-diazabicyclo<4.3.0>non-5-ene / diethyl ether / 3 h / Ambient temperature View Scheme

1: 1.) hydroxylamine sulfate, NaHCO3; 2.) 1,1'-carbonyldiimidazol / 1.) 10 deg C, 1 h, water and ether; 2.) CH2Cl2, room temp., overnight 2: 96 percent / Br2 / CH2Cl2; CHCl3 / 0.67 h / -70 °C 3: 42 percent / 1,4-diazabicyclo<4.3.0>non-5-ene / diethyl ether / 3 h / Ambient temperature View Scheme