1: 2) SnCl4 / 1) silylation, 2a) 1,2-dichloroethane, reflux, 6 h, 1,2-dichloroethane, 2b) r.t., overnight 2: 98 percent / NH3 / methanol / 48 h / Ambient temperature View Scheme

1: pyridine / -10 °C 2: Et2O*BF3 / 2 h / -20 °C 3: 71 percent / KI, dibenzo-18-crown-6 / acetonitrile; toluene / Heating 4: 44 percent / NH3 / methanol View Scheme

hydrogenchloride; potassium chloride; water T=40°C; ionic strength 0.89, E(excit.), ΔS(excit.); Rate constantMechanismThermodynamic data;