tetrafluoroboric acid diethyl ether complex in dichloromethane T=-78°C; 24 h;

manganese(IV) oxide in dichloromethane Heating;

1: With sodium tetrahydroborate in ethanol T=20°C; 20 h; 2: With hydrogenchloride in ethanol; water

1: NaBH4 / methanol 2: 62 percent / pyridinium chlorochromate / CH2Cl2 / 1.5 h 3: 74.8 percent / n-BuLi / 1.) THF, hexane, -40 deg C, 2.) THF, r.t., 5 h 4: 71 percent / alcoholic 2 N KOH 5: 80 percent / diethyl ether 6: 89 percent / LiAlH4 View Scheme

2-mesityl-2,5,6,7-tetrahydropyrrolo[2,1-c][1,2,4]triazol-4-ium chloride; 1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran T=20 - 25°C; 15 h;