1: 92 percent / pyridine / 5 h / 20 °C 2: 87 percent / Dowex 50H+ / methanol / 48 h / 60 °C 3: 89 percent / DMAP; pyridine / 50 °C 4: 95 percent / AcOH; H2SO4 / 0.5 h / 20 °C 5: 69 percent / stannic chloride / CH2Cl2 / 3 h / Heating 6: 71 percent / triethylamine / methanol / 2 h / 20 °C 7: 74 percent / bromotrichloromethane; 1,8-diazabicyclo[5.4.0]-undec-7-ene / CH2Cl2 / 16 h / 0 °C 8: 85 percent / NH3 / methanol / 24 h / 20 °C View Scheme

1: 1) 40percent aq. PTSA / 1) methylene chloride, acetone, 3h, 2) xylene, reflux, 30 min 2: 46 percent / ammonia / methanol / 48 h View Scheme

ammonia; ozone 1a) solid CO2- acetone cooling,1b) roomtemp., dichloromethane, 2) methanol, 72h; Yield given. Multistep reaction;

1: 73 percent / 1 N etheral HCl / various solvent(s) / Ambient temperature 2: phosphoryl chloride / various solvent(s) / 3 h / 4 °C 3: 11.4 mg / tri-n-octylamine / 1.) 60 deg C, 2 h, 2.) RT, overnight 4: 1.7 mg / 10percent aq. CH3COOH / 0.42 h / 70 °C View Scheme

1: 78 percent / 3 h / Temperature: from -20 deg C to room temp. 2: 70 percent / pyridine; CH2Cl2 / 3 h / 0 °C 3: 48 percent / hexamethylphosphoric acid triamide / 20 h / Ambient temperature 4: 1.) HF*Pyr, 2.) NH3 / 1.) THF, room temp., 2 days, 2.) methanol View Scheme

1: 78 percent / 3 h / Temperature: from -20 deg C to room temp. 2: pyridinium p-toluenesulfonate / CH2Cl2 / 24 h / Ambient temperature 3: HF*Pyr / tetrahydrofuran / 24 h / Ambient temperature 4: 4 h / Ambient temperature 5: 70 percent / pyridine; CH2Cl2 / 4 h / Temperature: from -20 deg C to 0 deg C 6: 97 percent / hexamethylphosphoric acid triamide; dimethylformamide / 20 h / Ambient temperature 7: 1.) NH3, 2.) aq. acetic acid / 1.) methanol, room temp., 2.) room temp. View Scheme